Как перевести число в дату python

How to Convert Integers to Datetime in Pandas in Python

In this Python tutorial, we will learn how to convert Integers to Datetime in Pandas DataFrame. Also, we will cover these topics.

• Convert int to datetime in Pandas
• Convert number to date in Pandas
• Convert excel number to date in Pandas
• Convert int column to datetime Pandas
• Pandas convert datetimeindex to integer
• Convert int to datetime in Pandas with nan
• Convert int to datetime in Pandas without decimal
• Convert int to datetime in Pandas string

Table of Contents

Convert Integers to Datetime in Pandas

• In this Program, we will discuss how to convert integers to Datetime in Pandas DataFrame by using Python.
• By using Pandas.Datetime() method we can perform this particular task and to do this task first you have to check that the integer data must match the format specified.

Syntax:

Here is the Syntax of Pandas.Datetime() method

Example:

Let’s take an example and check how to convert integers to datetime in Pandas Dataframe by using Python

In the above code, we have created three different dates with a format of (yyy-mm-dd). Now we will declare the dataframe object and assign dictionary ‘new_dict’ and column names in the list. Now use Pandas.to_Datetime() method to convert integers to Datetime.

Here is the execution of the following given code

Convert int to datetime in Pandas

• Let us see how to convert int to datetime in Pandas DataFrame by using Python.
• Here we can use the pd.to_datetime() method and this function will convert your integer data to a date format.

Syntax:

Here is the Syntax of pd.to_datetime() method

• It consists of few parameters
  • arg: This parameter specifies the object you want to convert to a datetime and object must be integer, string or float.
  • errors: By default, its value is ‘raise’ that represent the invalid parsing will raise an exception.
  • dayfirst: This parameter will help you to understand if your ‘day’ is first in your format and by default, its value is ‘False’.
  • yearfirst: It indicates if your year is first then try the format code option first and by default, it takes the ‘false’ value.
  • utc: This parameter is used if you want to convert your datetime with timezone.
  • format: This parameter is used to show the format codes of datetime.

  Source Code:

  In the above program, we have imported the Pandas library and then initialize an integer value with the variable name ‘new_int’. Now use the pd.to_datetime() method and assign str datatype along with ‘new_int’. Once you will print the ‘new_result’ then the output will display the Datetime format.

  You can refer to the below Screenshot

  

  Convert number to date in Pandas

  • In this section, we will discuss how to convert the number to date in Pandas Dataframe by using Python.
  • In this example, we have to convert an integer numbers to date in Pandas Dataframe. To perform this task first we are going to use the pd.to_datetime() method and this will help the user to convert the number with date in Dataframe.

  Example:

  In the above code, we have created a dataframe object ‘new_dt’ and then pass the integer variable name ‘new_val’ along with *3 which means it will display three times. Now use the lambda function and it evaluates an expression for a given argument.

  Here is the implementation of the following given code

  

  Convert excel number to date in Pandas

  • In this Program, we will discuss how to convert the excel number to date in Pandas DataFrame by using Python.
  • Here we can use an example of an excel number to do this task use a library called xlrd internally and this can be used for reading input files.
  • To install the xlrd package in Python you have to use the pip install xlrd command and this module allows the user to read data from an excel number or file.

  Syntax:

  Here is the Syntax of xldate_as_datetime

  Source Code:

  After installing ‘xlrd’ package you have to import xlrd library in example and now use the xldate_as_datetime() method to convert an excel number into a DateTime object.

  Here is the Output of the following given code

  

  Convert int column to datetime Pandas

  • Let us see how to convert integer columns to datetime by using Python Pandas.
  • In Python, if you want to convert a column to datetime then you can easily apply the pd.to_datetime() method. To perform this task first create a dataframe from the dictionary and then use the pd.dataframe class with the dictionary as input.
  • Now to convert integer column to datetime use the dataframe ‘df’ in brackets and within this bracket mention the column name which you want to convert with datetime.

  Source Code:

  Here is the Screenshot of the following given code

  

  Pandas convert datetimeindex to integer

  • In this section, we will discuss how to convert datetimeindex with an integer in Pandas Dataframe by using Python.
  • By using the combination of pd.to_timedelta() and dt.total_seconds() method we can perform this particular task easily. In Pandas the timedelta format is used for the addition of the date and time components along with that the total_seconds() method is directly available on Timedeltaindex and timedelta values.

  Syntax:

  Here is the Syntax of Pandas.to_delta() method

  • It consists of few parameters
    • arg: This parameter specifies the data object to be converted with time delta.
    • unit: By default its value is None and the values are ‘Y’,’M’,’W’,’D’.
    • errors: In this example we will set the errors=’ignore’.

    Example:

    Here is the execution of the following given code

    

    Convert int to datetime in Pandas with nan

    • In this Program, we will discuss how to convert integers to datetime in Pandas DataFrame with nan value.
    • Here we can use the Pandas.to_datetime() method to perform this task. First, we have to import pandas and numpy library and then create a dictionary ‘my_dict’ that contains key-value pair. In this example, the key has been considered as column name and the list values as integers.
    • In the given list we have assigned some integer and nan values it. Now we want to convert the integer with datetime along with nan.

    Source Code:

    You can refer to the below Screenshot

    

    As you can see in the Screenshot the output is shown the nan values have been replaced with ‘NAT’.In Python, the NAT represents the missing values.

    Convert int to datetime in Pandas without decimal

    • In this section, we will discuss how to convert integer to datetime in Pandas DataFrame.
    • We have already covered this topic in the beginning so you can better understand this example. In this example, we have applied the same method Pandas.to_datetime.

    Example:

    Here is the Screenshot of the following given code

    

    Convert int to datetime in Pandas string

    • In this Program, we will discuss how to convert integers to datetime in Pandas string.
    • By using the astype(str) method we can change the datatype of a series and this function also provides to convert the existing column to a different type.

    Syntax:

    Here is the Syntax of df.astype() method

    • It consists of a few parameters.
      • dtype: This parameter specifies the conversion of series with integer or string.
      • copy: By default it takes ‘True’ value and makes a copy of dataframe.
      • errors: This parameter indicates if a datatype is invalid then the error ‘raise’.

      Example:

      Here is the execution of the following given code

      

      You may also like to read the following tutorials.

      In this Python tutorial, we have learned how to convert Integers to Datetime in Pandas DataFrame. Also, we have covered these topics.

      • Convert int to datetime in Pandas
      • Convert number to date in Pandas
      • Convert excel number to date in Pandas
      • Convert int column to datetime Pandas
      • Pandas convert datetimeindex to integer
      • Convert int to datetime in Pandas with nan
      • Convert int to datetime in Pandas without decimal
      • Convert int to datetime in Pandas string

      

      I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.

      How to convert integer into date object python?

      I am creating a module in python, in which I am receiving the date in integer format like 20120213 , which signifies the 13th of Feb, 2012. Now, I want to convert this integer formatted date into a python date object.

      Also, if there is any means by which I can subtract/add the number of days in such integer formatted date to receive the date value in same format? like subtracting 30 days from 20120213 and receive answer as 20120114 ?

      8.1. datetime — Basic date and time types¶

      The datetime module supplies classes for manipulating dates and times in both simple and complex ways. While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation. For related functionality, see also the time and calendar modules.

      There are two kinds of date and time objects: “naive” and “aware”.

      An aware object has sufficient knowledge of applicable algorithmic and political time adjustments, such as time zone and daylight saving time information, to locate itself relative to other aware objects. An aware object is used to represent a specific moment in time that is not open to interpretation [1].

      A naive object does not contain enough information to unambiguously locate itself relative to other date/time objects. Whether a naive object represents Coordinated Universal Time (UTC), local time, or time in some other timezone is purely up to the program, just like it is up to the program whether a particular number represents metres, miles, or mass. Naive objects are easy to understand and to work with, at the cost of ignoring some aspects of reality.

      For applications requiring aware objects, datetime and time objects have an optional time zone information attribute, tzinfo , that can be set to an instance of a subclass of the abstract tzinfo class. These tzinfo objects capture information about the offset from UTC time, the time zone name, and whether Daylight Saving Time is in effect. Note that only one concrete tzinfo class, the timezone class, is supplied by the datetime module. The timezone class can represent simple timezones with fixed offset from UTC, such as UTC itself or North American EST and EDT timezones. Supporting timezones at deeper levels of detail is up to the application. The rules for time adjustment across the world are more political than rational, change frequently, and there is no standard suitable for every application aside from UTC.

      The datetime module exports the following constants:

      The smallest year number allowed in a date or datetime object. MINYEAR is 1 .

      The largest year number allowed in a date or datetime object. MAXYEAR is 9999 .

      Module calendar General calendar related functions. Module time Time access and conversions.

      8.1.1. Available Types¶

      An idealized naive date, assuming the current Gregorian calendar always was, and always will be, in effect. Attributes: year , month , and day .

      class datetime. time

      An idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds (there is no notion of “leap seconds” here). Attributes: hour , minute , second , microsecond , and tzinfo .

      class datetime. datetime

      A combination of a date and a time. Attributes: year , month , day , hour , minute , second , microsecond , and tzinfo .

      class datetime. timedelta

      A duration expressing the difference between two date , time , or datetime instances to microsecond resolution.

      class datetime. tzinfo

      An abstract base class for time zone information objects. These are used by the datetime and time classes to provide a customizable notion of time adjustment (for example, to account for time zone and/or daylight saving time).

      class datetime. timezone

      A class that implements the tzinfo abstract base class as a fixed offset from the UTC.

      New in version 3.2.

      Objects of these types are immutable.

      Objects of the date type are always naive.

      An object of type time or datetime may be naive or aware. A datetime object d is aware if d.tzinfo is not None and d.tzinfo.utcoffset(d) does not return None . If d.tzinfo is None , or if d.tzinfo is not None but d.tzinfo.utcoffset(d) returns None , d is naive. A time object t is aware if t.tzinfo is not None and t.tzinfo.utcoffset(None) does not return None . Otherwise, t is naive.

      The distinction between naive and aware doesn’t apply to timedelta objects.

      8.1.2. timedelta Objects¶

      A timedelta object represents a duration, the difference between two dates or times.

      class datetime. timedelta ( days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0 ) ¶

      All arguments are optional and default to 0 . Arguments may be integers or floats, and may be positive or negative.

      Only days, seconds and microseconds are stored internally. Arguments are converted to those units:

      • A millisecond is converted to 1000 microseconds.
      • A minute is converted to 60 seconds.
      • An hour is converted to 3600 seconds.
      • A week is converted to 7 days.

      and days, seconds and microseconds are then normalized so that the representation is unique, with

      • 0 <= microseconds < 1000000
      • 0 <= seconds < 3600*24 (the number of seconds in one day)
      • -999999999 <= days <= 999999999

      If any argument is a float and there are fractional microseconds, the fractional microseconds left over from all arguments are combined and their sum is rounded to the nearest microsecond using round-half-to-even tiebreaker. If no argument is a float, the conversion and normalization processes are exact (no information is lost).

      If the normalized value of days lies outside the indicated range, OverflowError is raised.

      Note that normalization of negative values may be surprising at first. For example,

      Class attributes are:

      The most negative timedelta object, timedelta(-999999999) .

      The most positive timedelta object, timedelta(days=999999999, hours=23, minutes=59, seconds=59, microseconds=999999) .

      The smallest possible difference between non-equal timedelta objects, timedelta(microseconds=1) .

      Note that, because of normalization, timedelta.max > -timedelta.min . -timedelta.max is not representable as a timedelta object.

      Instance attributes (read-only):

      Attribute	Value
      days	Between -999999999 and 999999999 inclusive
      seconds	Between 0 and 86399 inclusive
      microseconds	Between 0 and 999999 inclusive

      Operation	Result
      t1 = t2 + t3	Sum of t2 and t3. Afterwards t1—t2 == t3 and t1—t3 == t2 are true. (1)
      t1 = t2 — t3	Difference of t2 and t3. Afterwards t1 == t2 — t3 and t2 == t1 + t3 are true. (1)
      t1 = t2 * i or t1 = i * t2	Delta multiplied by an integer. Afterwards t1 // i == t2 is true, provided i != 0 .
      	In general, t1 * i == t1 * (i-1) + t1 is true. (1)
      t1 = t2 * f or t1 = f * t2	Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
      f = t2 / t3	Division (3) of t2 by t3. Returns a float object.
      t1 = t2 / f or t1 = t2 / i	Delta divided by a float or an int. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
      t1 = t2 // i or t1 = t2 // t3	The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
      t1 = t2 % t3	The remainder is computed as a timedelta object. (3)
      q, r = divmod(t1, t2)	Computes the quotient and the remainder: q = t1 // t2 (3) and r = t1 % t2 . q is an integer and r is a timedelta object.
      +t1	Returns a timedelta object with the same value. (2)
      -t1	equivalent to timedelta (-t1.days, —t1.seconds, —t1.microseconds), and to t1* -1. (1)(4)
      abs(t)	equivalent to +t when t.days >= 0 , and to —t when t.days < 0 . (2)
      str(t)	Returns a string in the form [D day[s], ][H]H:MM:SS[.UUUUUU] , where D is negative for negative t . (5)
      repr(t)	Returns a string in the form datetime.timedelta(D[, S[, U]]) , where D is negative for negative t . (5)

      This is exact, but may overflow.

      This is exact, and cannot overflow.

      —timedelta.max is not representable as a timedelta object.

      String representations of timedelta objects are normalized similarly to their internal representation. This leads to somewhat unusual results for negative timedeltas. For example:

      In addition to the operations listed above timedelta objects support certain additions and subtractions with date and datetime objects (see below).

      Changed in version 3.2: Floor division and true division of a timedelta object by another timedelta object are now supported, as are remainder operations and the divmod() function. True division and multiplication of a timedelta object by a float object are now supported.

      Comparisons of timedelta objects are supported with the timedelta object representing the smaller duration considered to be the smaller timedelta. In order to stop mixed-type comparisons from falling back to the default comparison by object address, when a timedelta object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      timedelta objects are hashable (usable as dictionary keys), support efficient pickling, and in Boolean contexts, a timedelta object is considered to be true if and only if it isn’t equal to timedelta(0) .

      Return the total number of seconds contained in the duration. Equivalent to td / timedelta(seconds=1) .

      Note that for very large time intervals (greater than 270 years on most platforms) this method will lose microsecond accuracy.

      New in version 3.2.

      8.1.3. date Objects¶

      A date object represents a date (year, month and day) in an idealized calendar, the current Gregorian calendar indefinitely extended in both directions. January 1 of year 1 is called day number 1, January 2 of year 1 is called day number 2, and so on. This matches the definition of the “proleptic Gregorian” calendar in Dershowitz and Reingold’s book Calendrical Calculations, where it’s the base calendar for all computations. See the book for algorithms for converting between proleptic Gregorian ordinals and many other calendar systems.

      All arguments are required. Arguments may be integers, in the following ranges:

      • MINYEAR <= year <= MAXYEAR
      • 1 <= month <= 12
      • 1 <= day <= number of days in the given month and year

      If an argument outside those ranges is given, ValueError is raised.

      Other constructors, all class methods:

      classmethod date. today ( ) ¶

      Return the current local date. This is equivalent to date.fromtimestamp(time.time()) .

      classmethod date. fromtimestamp ( timestamp ) ¶

      Return the local date corresponding to the POSIX timestamp, such as is returned by time.time() . This may raise OverflowError , if the timestamp is out of the range of values supported by the platform C localtime() function, and OSError on localtime() failure. It’s common for this to be restricted to years from 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp() .

      Changed in version 3.3: Raise OverflowError instead of ValueError if the timestamp is out of the range of values supported by the platform C localtime() function. Raise OSError instead of ValueError on localtime() failure.

      Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. ValueError is raised unless 1 <= ordinal <= date.max.toordinal() . For any date d, date.fromordinal(d.toordinal()) == d .

      The earliest representable date, date(MINYEAR, 1, 1) .

      The latest representable date, date(MAXYEAR, 12, 31) .

      The smallest possible difference between non-equal date objects, timedelta(days=1) .

      Instance attributes (read-only):

      Between MINYEAR and MAXYEAR inclusive.

      Between 1 and 12 inclusive.

      Between 1 and the number of days in the given month of the given year.

      Operation	Result
      date2 = date1 + timedelta	date2 is timedelta.days days removed from date1. (1)
      date2 = date1 — timedelta	Computes date2 such that date2 + timedelta == date1 . (2)
      timedelta = date1 — date2	(3)
      date1 < date2	date1 is considered less than date2 when date1 precedes date2 in time. (4)

      1. date2 is moved forward in time if timedelta.days > 0 , or backward if timedelta.days < 0 . Afterward date2 — date1 == timedelta.days . timedelta.seconds and timedelta.microseconds are ignored. OverflowError is raised if date2.year would be smaller than MINYEAR or larger than MAXYEAR .
      2. This isn’t quite equivalent to date1 + (-timedelta), because -timedelta in isolation can overflow in cases where date1 — timedelta does not. timedelta.seconds and timedelta.microseconds are ignored.
      3. This is exact, and cannot overflow. timedelta.seconds and timedelta.microseconds are 0, and date2 + timedelta == date1 after.
      4. In other words, date1 < date2 if and only if date1.toordinal() < date2.toordinal() . In order to stop comparison from falling back to the default scheme of comparing object addresses, date comparison normally raises TypeError if the other comparand isn’t also a date object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a date object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      Dates can be used as dictionary keys. In Boolean contexts, all date objects are considered to be true.

      date. replace ( year=self.year, month=self.month, day=self.day ) ¶

      Return a date with the same value, except for those parameters given new values by whichever keyword arguments are specified. For example, if d == date(2002, 12, 31) , then d.replace(day=26) == date(2002, 12, 26) .

      Return a time.struct_time such as returned by time.localtime() . The hours, minutes and seconds are 0, and the DST flag is -1. d.timetuple() is equivalent to time.struct_time((d.year, d.month, d.day, 0, 0, 0, d.weekday(), yday, -1)) , where yday = d.toordinal() — date(d.year, 1, 1).toordinal() + 1 is the day number within the current year starting with 1 for January 1st.

      Return the proleptic Gregorian ordinal of the date, where January 1 of year 1 has ordinal 1. For any date object d, date.fromordinal(d.toordinal()) == d .

      Return the day of the week as an integer, where Monday is 0 and Sunday is 6. For example, date(2002, 12, 4).weekday() == 2 , a Wednesday. See also isoweekday() .

      Return the day of the week as an integer, where Monday is 1 and Sunday is 7. For example, date(2002, 12, 4).isoweekday() == 3 , a Wednesday. See also weekday() , isocalendar() .

      Return a 3-tuple, (ISO year, ISO week number, ISO weekday).

      The ISO calendar is a widely used variant of the Gregorian calendar. See https://www.staff.science.uu.nl/

      The ISO year consists of 52 or 53 full weeks, and where a week starts on a Monday and ends on a Sunday. The first week of an ISO year is the first (Gregorian) calendar week of a year containing a Thursday. This is called week number 1, and the ISO year of that Thursday is the same as its Gregorian year.

      For example, 2004 begins on a Thursday, so the first week of ISO year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan 2004, so that date(2003, 12, 29).isocalendar() == (2004, 1, 1) and date(2004, 1, 4).isocalendar() == (2004, 1, 7) .

      Return a string representing the date in ISO 8601 format, ‘YYYY-MM-DD’. For example, date(2002, 12, 4).isoformat() == ‘2002-12-04’ .

      For a date d, str(d) is equivalent to d.isoformat() .

      Return a string representing the date, for example date(2002, 12, 4).ctime() == ‘Wed Dec 4 00:00:00 2002’ . d.ctime() is equivalent to time.ctime(time.mktime(d.timetuple())) on platforms where the native C ctime() function (which time.ctime() invokes, but which date.ctime() does not invoke) conforms to the C standard.

      date. strftime ( format ) ¶

      Return a string representing the date, controlled by an explicit format string. Format codes referring to hours, minutes or seconds will see 0 values. For a complete list of formatting directives, see strftime() and strptime() Behavior .

      date. __format__ ( format ) ¶

      Same as date.strftime() . This makes it possible to specify a format string for a date object in formatted string literals and when using str.format() . For a complete list of formatting directives, see strftime() and strptime() Behavior .

      Example of counting days to an event:

      Example of working with date :

      8.1.4. datetime Objects¶

      A datetime object is a single object containing all the information from a date object and a time object. Like a date object, datetime assumes the current Gregorian calendar extended in both directions; like a time object, datetime assumes there are exactly 3600*24 seconds in every day.

      The year, month and day arguments are required. tzinfo may be None , or an instance of a tzinfo subclass. The remaining arguments may be integers, in the following ranges:

      • MINYEAR <= year <= MAXYEAR ,
      • 1 <= month <= 12 ,
      • 1 <= day <= number of days in the given month and year ,
      • 0 <= hour < 24 ,
      • 0 <= minute < 60 ,
      • 0 <= second < 60 ,
      • 0 <= microsecond < 1000000 ,
      • fold in [0, 1] .

      If an argument outside those ranges is given, ValueError is raised.

      New in version 3.6: Added the fold argument.

      Other constructors, all class methods:

      classmethod datetime. today ( ) ¶

      Return the current local datetime, with tzinfo None . This is equivalent to datetime.fromtimestamp(time.time()) . See also now() , fromtimestamp() .

      classmethod datetime. now ( tz=None ) ¶

      Return the current local date and time. If optional argument tz is None or not specified, this is like today() , but, if possible, supplies more precision than can be gotten from going through a time.time() timestamp (for example, this may be possible on platforms supplying the C gettimeofday() function).

      If tz is not None , it must be an instance of a tzinfo subclass, and the current date and time are converted to tz’s time zone. In this case the result is equivalent to tz.fromutc(datetime.utcnow().replace(tzinfo=tz)) . See also today() , utcnow() .

      classmethod datetime. utcnow ( ) ¶

      Return the current UTC date and time, with tzinfo None . This is like now() , but returns the current UTC date and time, as a naive datetime object. An aware current UTC datetime can be obtained by calling datetime.now(timezone.utc) . See also now() .

      classmethod datetime. fromtimestamp ( timestamp, tz=None ) ¶

      Return the local date and time corresponding to the POSIX timestamp, such as is returned by time.time() . If optional argument tz is None or not specified, the timestamp is converted to the platform’s local date and time, and the returned datetime object is naive.

      If tz is not None , it must be an instance of a tzinfo subclass, and the timestamp is converted to tz’s time zone. In this case the result is equivalent to tz.fromutc(datetime.utcfromtimestamp(timestamp).replace(tzinfo=tz)) .

      fromtimestamp() may raise OverflowError , if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions, and OSError on localtime() or gmtime() failure. It’s common for this to be restricted to years in 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp() , and then it’s possible to have two timestamps differing by a second that yield identical datetime objects. See also utcfromtimestamp() .

      Changed in version 3.3: Raise OverflowError instead of ValueError if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions. Raise OSError instead of ValueError on localtime() or gmtime() failure.

      Changed in version 3.6: fromtimestamp() may return instances with fold set to 1.

      Return the UTC datetime corresponding to the POSIX timestamp, with tzinfo None . This may raise OverflowError , if the timestamp is out of the range of values supported by the platform C gmtime() function, and OSError on gmtime() failure. It’s common for this to be restricted to years in 1970 through 2038.

      To get an aware datetime object, call fromtimestamp() :

      On the POSIX compliant platforms, it is equivalent to the following expression:

      except the latter formula always supports the full years range: between MINYEAR and MAXYEAR inclusive.

      Changed in version 3.3: Raise OverflowError instead of ValueError if the timestamp is out of the range of values supported by the platform C gmtime() function. Raise OSError instead of ValueError on gmtime() failure.

      Return the datetime corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. ValueError is raised unless 1 <= ordinal <= datetime.max.toordinal() . The hour, minute, second and microsecond of the result are all 0, and tzinfo is None .

      classmethod datetime. combine ( date, time, tzinfo=self.tzinfo ) ¶

      Return a new datetime object whose date components are equal to the given date object’s, and whose time components are equal to the given time object’s. If the tzinfo argument is provided, its value is used to set the tzinfo attribute of the result, otherwise the tzinfo attribute of the time argument is used.

      For any datetime object d, d == datetime.combine(d.date(), d.time(), d.tzinfo) . If date is a datetime object, its time components and tzinfo attributes are ignored.

      Changed in version 3.6: Added the tzinfo argument.

      Return a datetime corresponding to date_string, parsed according to format. This is equivalent to datetime(*(time.strptime(date_string, format)[0:6])) . ValueError is raised if the date_string and format can’t be parsed by time.strptime() or if it returns a value which isn’t a time tuple. For a complete list of formatting directives, see strftime() and strptime() Behavior .

      The earliest representable datetime , datetime(MINYEAR, 1, 1, tzinfo=None) .

      The latest representable datetime , datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, tzinfo=None) .

      The smallest possible difference between non-equal datetime objects, timedelta(microseconds=1) .

      Instance attributes (read-only):

      Between MINYEAR and MAXYEAR inclusive.

      Between 1 and 12 inclusive.

      Between 1 and the number of days in the given month of the given year.

      The object passed as the tzinfo argument to the datetime constructor, or None if none was passed.

      In [0, 1] . Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The value 0 (1) represents the earlier (later) of the two moments with the same wall time representation.

      New in version 3.6.

      datetime2 is a duration of timedelta removed from datetime1, moving forward in time if timedelta.days > 0, or backward if timedelta.days < 0. The result has the same tzinfo attribute as the input datetime, and datetime2 — datetime1 == timedelta after. OverflowError is raised if datetime2.year would be smaller than MINYEAR or larger than MAXYEAR . Note that no time zone adjustments are done even if the input is an aware object.

      Computes the datetime2 such that datetime2 + timedelta == datetime1. As for addition, the result has the same tzinfo attribute as the input datetime, and no time zone adjustments are done even if the input is aware. This isn’t quite equivalent to datetime1 + (-timedelta), because -timedelta in isolation can overflow in cases where datetime1 — timedelta does not.

      Subtraction of a datetime from a datetime is defined only if both operands are naive, or if both are aware. If one is aware and the other is naive, TypeError is raised.

      If both are naive, or both are aware and have the same tzinfo attribute, the tzinfo attributes are ignored, and the result is a timedelta object t such that datetime2 + t == datetime1 . No time zone adjustments are done in this case.

      If both are aware and have different tzinfo attributes, a-b acts as if a and b were first converted to naive UTC datetimes first. The result is (a.replace(tzinfo=None) — a.utcoffset()) — (b.replace(tzinfo=None) — b.utcoffset()) except that the implementation never overflows.

      datetime1 is considered less than datetime2 when datetime1 precedes datetime2 in time.

      If one comparand is naive and the other is aware, TypeError is raised if an order comparison is attempted. For equality comparisons, naive instances are never equal to aware instances.

      If both comparands are aware, and have the same tzinfo attribute, the common tzinfo attribute is ignored and the base datetimes are compared. If both comparands are aware and have different tzinfo attributes, the comparands are first adjusted by subtracting their UTC offsets (obtained from self.utcoffset() ).

      Changed in version 3.3: Equality comparisons between naive and aware datetime instances don’t raise TypeError .

      In order to stop comparison from falling back to the default scheme of comparing object addresses, datetime comparison normally raises TypeError if the other comparand isn’t also a datetime object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a datetime object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      datetime objects can be used as dictionary keys. In Boolean contexts, all datetime objects are considered to be true.

      Return date object with same year, month and day.

      Return time object with same hour, minute, second, microsecond and fold. tzinfo is None . See also method timetz() .

      Changed in version 3.6: The fold value is copied to the returned time object.

      Return time object with same hour, minute, second, microsecond, fold, and tzinfo attributes. See also method time() .

      Changed in version 3.6: The fold value is copied to the returned time object.

      Return a datetime with the same attributes, except for those attributes given new values by whichever keyword arguments are specified. Note that tzinfo=None can be specified to create a naive datetime from an aware datetime with no conversion of date and time data.

      New in version 3.6: Added the fold argument.

      Return a datetime object with new tzinfo attribute tz, adjusting the date and time data so the result is the same UTC time as self, but in tz‘s local time.

      If provided, tz must be an instance of a tzinfo subclass, and its utcoffset() and dst() methods must not return None . If self is naive ( self.tzinfo is None ), it is presumed to represent time in the system timezone.

      If called without arguments (or with tz=None ) the system local timezone is assumed for the target timezone. The .tzinfo attribute of the converted datetime instance will be set to an instance of timezone with the zone name and offset obtained from the OS.

      If self.tzinfo is tz, self.astimezone(tz) is equal to self: no adjustment of date or time data is performed. Else the result is local time in the timezone tz, representing the same UTC time as self: after astz = dt.astimezone(tz) , astz — astz.utcoffset() will have the same date and time data as dt — dt.utcoffset() .

      If you merely want to attach a time zone object tz to a datetime dt without adjustment of date and time data, use dt.replace(tzinfo=tz) . If you merely want to remove the time zone object from an aware datetime dt without conversion of date and time data, use dt.replace(tzinfo=None) .

      Note that the default tzinfo.fromutc() method can be overridden in a tzinfo subclass to affect the result returned by astimezone() . Ignoring error cases, astimezone() acts like:

      Changed in version 3.3: tz now can be omitted.

      Changed in version 3.6: The astimezone() method can now be called on naive instances that are presumed to represent system local time.

      If tzinfo is None , returns None , else returns self.tzinfo.utcoffset(self) , and raises an exception if the latter doesn’t return None , or a timedelta object representing a whole number of minutes with magnitude less than one day.

      If tzinfo is None , returns None , else returns self.tzinfo.dst(self) , and raises an exception if the latter doesn’t return None , or a timedelta object representing a whole number of minutes with magnitude less than one day.

      If tzinfo is None , returns None , else returns self.tzinfo.tzname(self) , raises an exception if the latter doesn’t return None or a string object,

      Return a time.struct_time such as returned by time.localtime() . d.timetuple() is equivalent to time.struct_time((d.year, d.month, d.day, d.hour, d.minute, d.second, d.weekday(), yday, dst)) , where yday = d.toordinal() — date(d.year, 1, 1).toordinal() + 1 is the day number within the current year starting with 1 for January 1st. The tm_isdst flag of the result is set according to the dst() method: tzinfo is None or dst() returns None , tm_isdst is set to -1 ; else if dst() returns a non-zero value, tm_isdst is set to 1 ; else tm_isdst is set to 0 .

      If datetime instance d is naive, this is the same as d.timetuple() except that tm_isdst is forced to 0 regardless of what d.dst() returns. DST is never in effect for a UTC time.

      If d is aware, d is normalized to UTC time, by subtracting d.utcoffset() , and a time.struct_time for the normalized time is returned. tm_isdst is forced to 0. Note that an OverflowError may be raised if d.year was MINYEAR or MAXYEAR and UTC adjustment spills over a year boundary.

      Return the proleptic Gregorian ordinal of the date. The same as self.date().toordinal() .

      Return POSIX timestamp corresponding to the datetime instance. The return value is a float similar to that returned by time.time() .

      Naive datetime instances are assumed to represent local time and this method relies on the platform C mktime() function to perform the conversion. Since datetime supports wider range of values than mktime() on many platforms, this method may raise OverflowError for times far in the past or far in the future.

      For aware datetime instances, the return value is computed as:

      New in version 3.3.

      Changed in version 3.6: The timestamp() method uses the fold attribute to disambiguate the times during a repeated interval.

      There is no method to obtain the POSIX timestamp directly from a naive datetime instance representing UTC time. If your application uses this convention and your system timezone is not set to UTC, you can obtain the POSIX timestamp by supplying tzinfo=timezone.utc :

      or by calculating the timestamp directly:

      Return the day of the week as an integer, where Monday is 0 and Sunday is 6. The same as self.date().weekday() . See also isoweekday() .

      Return the day of the week as an integer, where Monday is 1 and Sunday is 7. The same as self.date().isoweekday() . See also weekday() , isocalendar() .

      Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The same as self.date().isocalendar() .

      datetime. isoformat ( sep=’T’, timespec=’auto’ ) ¶

      Return a string representing the date and time in ISO 8601 format, YYYY-MM-DDTHH:MM:SS.mmmmmm or, if microsecond is 0, YYYY-MM-DDTHH:MM:SS

      If utcoffset() does not return None , a 6-character string is appended, giving the UTC offset in (signed) hours and minutes: YYYY-MM-DDTHH:MM:SS.mmmmmm+HH:MM or, if microsecond is 0 YYYY-MM-DDTHH:MM:SS+HH:MM

      The optional argument sep (default ‘T’ ) is a one-character separator, placed between the date and time portions of the result. For example,

      The optional argument timespec specifies the number of additional components of the time to include (the default is ‘auto’ ). It can be one of the following:

      • ‘auto’ : Same as ‘seconds’ if microsecond is 0, same as ‘microseconds’ otherwise.
      • ‘hours’ : Include the hour in the two-digit HH format.
      • ‘minutes’ : Include hour and minute in HH:MM format.
      • ‘seconds’ : Include hour , minute , and second in HH:MM:SS format.
      • ‘milliseconds’ : Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.
      • ‘microseconds’ : Include full time in HH:MM:SS.mmmmmm format.

      Excluded time components are truncated, not rounded.

      ValueError will be raised on an invalid timespec argument.

      New in version 3.6: Added the timespec argument.

      For a datetime instance d, str(d) is equivalent to d.isoformat(‘ ‘) .

      Return a string representing the date and time, for example datetime(2002, 12, 4, 20, 30, 40).ctime() == ‘Wed Dec   4 20:30:40 2002’ . d.ctime() is equivalent to time.ctime(time.mktime(d.timetuple())) on platforms where the native C ctime() function (which time.ctime() invokes, but which datetime.ctime() does not invoke) conforms to the C standard.

      datetime. strftime ( format ) ¶

      Return a string representing the date and time, controlled by an explicit format string. For a complete list of formatting directives, see strftime() and strptime() Behavior .

      datetime. __format__ ( format ) ¶

      Same as datetime.strftime() . This makes it possible to specify a format string for a datetime object in formatted string literals and when using str.format() . For a complete list of formatting directives, see strftime() and strptime() Behavior .

      Examples of working with datetime objects:

      Using datetime with tzinfo:

      8.1.5. time Objects¶

      A time object represents a (local) time of day, independent of any particular day, and subject to adjustment via a tzinfo object.

      All arguments are optional. tzinfo may be None , or an instance of a tzinfo subclass. The remaining arguments may be integers, in the following ranges:

      • 0 <= hour < 24 ,
      • 0 <= minute < 60 ,
      • 0 <= second < 60 ,
      • 0 <= microsecond < 1000000 ,
      • fold in [0, 1] .

      If an argument outside those ranges is given, ValueError is raised. All default to 0 except tzinfo, which defaults to None .

      The earliest representable time , time(0, 0, 0, 0) .

      The latest representable time , time(23, 59, 59, 999999) .

      The smallest possible difference between non-equal time objects, timedelta(microseconds=1) , although note that arithmetic on time objects is not supported.

      Instance attributes (read-only):

      The object passed as the tzinfo argument to the time constructor, or None if none was passed.

      In [0, 1] . Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The value 0 (1) represents the earlier (later) of the two moments with the same wall time representation.

      New in version 3.6.

      comparison of time to time , where a is considered less than b when a precedes b in time. If one comparand is naive and the other is aware, TypeError is raised if an order comparison is attempted. For equality comparisons, naive instances are never equal to aware instances.

      If both comparands are aware, and have the same tzinfo attribute, the common tzinfo attribute is ignored and the base times are compared. If both comparands are aware and have different tzinfo attributes, the comparands are first adjusted by subtracting their UTC offsets (obtained from self.utcoffset() ). In order to stop mixed-type comparisons from falling back to the default comparison by object address, when a time object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      Changed in version 3.3: Equality comparisons between naive and aware time instances don’t raise TypeError .

      hash, use as dict key

      In boolean contexts, a time object is always considered to be true.

      Changed in version 3.5: Before Python 3.5, a time object was considered to be false if it represented midnight in UTC. This behavior was considered obscure and error-prone and has been removed in Python 3.5. See bpo-13936 for full details.

      time. replace ( hour=self.hour, minute=self.minute, second=self.second, microsecond=self.microsecond, tzinfo=self.tzinfo, * fold=0 ) ¶

      Return a time with the same value, except for those attributes given new values by whichever keyword arguments are specified. Note that tzinfo=None can be specified to create a naive time from an aware time , without conversion of the time data.

      New in version 3.6: Added the fold argument.

      Return a string representing the time in ISO 8601 format, HH:MM:SS.mmmmmm or, if microsecond is 0, HH:MM:SS If utcoffset() does not return None , a 6-character string is appended, giving the UTC offset in (signed) hours and minutes: HH:MM:SS.mmmmmm+HH:MM or, if self.microsecond is 0, HH:MM:SS+HH:MM

      The optional argument timespec specifies the number of additional components of the time to include (the default is ‘auto’ ). It can be one of the following:

      • ‘auto’ : Same as ‘seconds’ if microsecond is 0, same as ‘microseconds’ otherwise.
      • ‘hours’ : Include the hour in the two-digit HH format.
      • ‘minutes’ : Include hour and minute in HH:MM format.
      • ‘seconds’ : Include hour , minute , and second in HH:MM:SS format.
      • ‘milliseconds’ : Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.
      • ‘microseconds’ : Include full time in HH:MM:SS.mmmmmm format.

      Excluded time components are truncated, not rounded.

      ValueError will be raised on an invalid timespec argument.

      New in version 3.6: Added the timespec argument.

      For a time t, str(t) is equivalent to t.isoformat() .

      time. strftime ( format ) ¶

      Return a string representing the time, controlled by an explicit format string. For a complete list of formatting directives, see strftime() and strptime() Behavior .

      time. __format__ ( format ) ¶

      Same as time.strftime() . This makes it possible to specify a format string for a time object in formatted string literals and when using str.format() . For a complete list of formatting directives, see strftime() and strptime() Behavior .

      If tzinfo is None , returns None , else returns self.tzinfo.utcoffset(None) , and raises an exception if the latter doesn’t return None or a timedelta object representing a whole number of minutes with magnitude less than one day.

      If tzinfo is None , returns None , else returns self.tzinfo.dst(None) , and raises an exception if the latter doesn’t return None , or a timedelta object representing a whole number of minutes with magnitude less than one day.

      If tzinfo is None , returns None , else returns self.tzinfo.tzname(None) , or raises an exception if the latter doesn’t return None or a string object.

      8.1.6. tzinfo Objects¶

      This is an abstract base class, meaning that this class should not be instantiated directly. You need to derive a concrete subclass, and (at least) supply implementations of the standard tzinfo methods needed by the datetime methods you use. The datetime module supplies a simple concrete subclass of tzinfo , timezone , which can represent timezones with fixed offset from UTC such as UTC itself or North American EST and EDT.

      An instance of (a concrete subclass of) tzinfo can be passed to the constructors for datetime and time objects. The latter objects view their attributes as being in local time, and the tzinfo object supports methods revealing offset of local time from UTC, the name of the time zone, and DST offset, all relative to a date or time object passed to them.

      Special requirement for pickling: A tzinfo subclass must have an __init__() method that can be called with no arguments, else it can be pickled but possibly not unpickled again. This is a technical requirement that may be relaxed in the future.

      A concrete subclass of tzinfo may need to implement the following methods. Exactly which methods are needed depends on the uses made of aware datetime objects. If in doubt, simply implement all of them.

      tzinfo. utcoffset ( dt ) ¶

      Return offset of local time from UTC, in minutes east of UTC. If local time is west of UTC, this should be negative. Note that this is intended to be the total offset from UTC; for example, if a tzinfo object represents both time zone and DST adjustments, utcoffset() should return their sum. If the UTC offset isn’t known, return None . Else the value returned must be a timedelta object specifying a whole number of minutes in the range -1439 to 1439 inclusive (1440 = 24*60; the magnitude of the offset must be less than one day). Most implementations of utcoffset() will probably look like one of these two:

      If utcoffset() does not return None , dst() should not return None either.

      The default implementation of utcoffset() raises NotImplementedError .

      Return the daylight saving time (DST) adjustment, in minutes east of UTC, or None if DST information isn’t known. Return timedelta(0) if DST is not in effect. If DST is in effect, return the offset as a timedelta object (see utcoffset() for details). Note that DST offset, if applicable, has already been added to the UTC offset returned by utcoffset() , so there’s no need to consult dst() unless you’re interested in obtaining DST info separately. For example, datetime.timetuple() calls its tzinfo attribute’s dst() method to determine how the tm_isdst flag should be set, and tzinfo.fromutc() calls dst() to account for DST changes when crossing time zones.

      An instance tz of a tzinfo subclass that models both standard and daylight times must be consistent in this sense:

      must return the same result for every datetime dt with dt.tzinfo == tz For sane tzinfo subclasses, this expression yields the time zone’s “standard offset”, which should not depend on the date or the time, but only on geographic location. The implementation of datetime.astimezone() relies on this, but cannot detect violations; it’s the programmer’s responsibility to ensure it. If a tzinfo subclass cannot guarantee this, it may be able to override the default implementation of tzinfo.fromutc() to work correctly with astimezone() regardless.

      Most implementations of dst() will probably look like one of these two:

      The default implementation of dst() raises NotImplementedError .

      tzinfo. tzname ( dt ) ¶

      Return the time zone name corresponding to the datetime object dt, as a string. Nothing about string names is defined by the datetime module, and there’s no requirement that it mean anything in particular. For example, “GMT”, “UTC”, “-500”, “-5:00”, “EDT”, “US/Eastern”, “America/New York” are all valid replies. Return None if a string name isn’t known. Note that this is a method rather than a fixed string primarily because some tzinfo subclasses will wish to return different names depending on the specific value of dt passed, especially if the tzinfo class is accounting for daylight time.

      The default implementation of tzname() raises NotImplementedError .

      These methods are called by a datetime or time object, in response to their methods of the same names. A datetime object passes itself as the argument, and a time object passes None as the argument. A tzinfo subclass’s methods should therefore be prepared to accept a dt argument of None , or of class datetime .

      When None is passed, it’s up to the class designer to decide the best response. For example, returning None is appropriate if the class wishes to say that time objects don’t participate in the tzinfo protocols. It may be more useful for utcoffset(None) to return the standard UTC offset, as there is no other convention for discovering the standard offset.

      When a datetime object is passed in response to a datetime method, dt.tzinfo is the same object as self. tzinfo methods can rely on this, unless user code calls tzinfo methods directly. The intent is that the tzinfo methods interpret dt as being in local time, and not need worry about objects in other timezones.

      There is one more tzinfo method that a subclass may wish to override:

      tzinfo. fromutc ( dt ) ¶

      This is called from the default datetime.astimezone() implementation. When called from that, dt.tzinfo is self, and dt‘s date and time data are to be viewed as expressing a UTC time. The purpose of fromutc() is to adjust the date and time data, returning an equivalent datetime in self‘s local time.

      Most tzinfo subclasses should be able to inherit the default fromutc() implementation without problems. It’s strong enough to handle fixed-offset time zones, and time zones accounting for both standard and daylight time, and the latter even if the DST transition times differ in different years. An example of a time zone the default fromutc() implementation may not handle correctly in all cases is one where the standard offset (from UTC) depends on the specific date and time passed, which can happen for political reasons. The default implementations of astimezone() and fromutc() may not produce the result you want if the result is one of the hours straddling the moment the standard offset changes.

      Skipping code for error cases, the default fromutc() implementation acts like:

      Note that there are unavoidable subtleties twice per year in a tzinfo subclass accounting for both standard and daylight time, at the DST transition points. For concreteness, consider US Eastern (UTC -0500), where EDT begins the minute after 1:59 (EST) on the second Sunday in March, and ends the minute after 1:59 (EDT) on the first Sunday in November:

      When DST starts (the “start” line), the local wall clock leaps from 1:59 to 3:00. A wall time of the form 2:MM doesn’t really make sense on that day, so astimezone(Eastern) won’t deliver a result with hour == 2 on the day DST begins. For example, at the Spring forward transition of 2016, we get

      When DST ends (the “end” line), there’s a potentially worse problem: there’s an hour that can’t be spelled unambiguously in local wall time: the last hour of daylight time. In Eastern, that’s times of the form 5:MM UTC on the day daylight time ends. The local wall clock leaps from 1:59 (daylight time) back to 1:00 (standard time) again. Local times of the form 1:MM are ambiguous. astimezone() mimics the local clock’s behavior by mapping two adjacent UTC hours into the same local hour then. In the Eastern example, UTC times of the form 5:MM and 6:MM both map to 1:MM when converted to Eastern, but earlier times have the fold attribute set to 0 and the later times have it set to 1. For example, at the Fall back transition of 2016, we get

      Note that the datetime instances that differ only by the value of the fold attribute are considered equal in comparisons.

      Applications that can’t bear wall-time ambiguities should explicitly check the value of the fold attribute or avoid using hybrid tzinfo subclasses; there are no ambiguities when using timezone , or any other fixed-offset tzinfo subclass (such as a class representing only EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)).

      The standard library has timezone class for handling arbitrary fixed offsets from UTC and timezone.utc as UTC timezone instance.

      dateutil.tz library brings the IANA timezone database (also known as the Olson database) to Python and its usage is recommended.

      IANA timezone database The Time Zone Database (often called tz, tzdata or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.

      8.1.7. timezone Objects¶

      The timezone class is a subclass of tzinfo , each instance of which represents a timezone defined by a fixed offset from UTC. Note that objects of this class cannot be used to represent timezone information in the locations where different offsets are used in different days of the year or where historical changes have been made to civil time.

      class datetime. timezone ( offset, name=None ) ¶

      The offset argument must be specified as a timedelta object representing the difference between the local time and UTC. It must be strictly between -timedelta(hours=24) and timedelta(hours=24) and represent a whole number of minutes, otherwise ValueError is raised.

      The name argument is optional. If specified it must be a string that will be used as the value returned by the datetime.tzname() method.

      New in version 3.2.

      Return the fixed value specified when the timezone instance is constructed. The dt argument is ignored. The return value is a timedelta instance equal to the difference between the local time and UTC.

      timezone. tzname ( dt ) ¶

      Return the fixed value specified when the timezone instance is constructed. If name is not provided in the constructor, the name returned by tzname(dt) is generated from the value of the offset as follows. If offset is timedelta(0) , the name is “UTC”, otherwise it is a string ‘UTC±HH:MM’, where ± is the sign of offset , HH and MM are two digits of offset.hours and offset.minutes respectively.

      Changed in version 3.6: Name generated from offset=timedelta(0) is now plain ‘UTC’, not ‘UTC+00:00’.

      Always returns None .

      timezone. fromutc ( dt ) ¶

      Return dt + offset . The dt argument must be an aware datetime instance, with tzinfo set to self .

      The UTC timezone, timezone(timedelta(0)) .

      8.1.8. strftime() and strptime() Behavior¶

      date , datetime , and time objects all support a strftime(format) method, to create a string representing the time under the control of an explicit format string. Broadly speaking, d.strftime(fmt) acts like the time module’s time.strftime(fmt, d.timetuple()) although not all objects support a timetuple() method.

      Conversely, the datetime.strptime() class method creates a datetime object from a string representing a date and time and a corresponding format string. datetime.strptime(date_string, format) is equivalent to datetime(*(time.strptime(date_string, format)[0:6])) .

      For time objects, the format codes for year, month, and day should not be used, as time objects have no such values. If they’re used anyway, 1900 is substituted for the year, and 1 for the month and day.

      For date objects, the format codes for hours, minutes, seconds, and microseconds should not be used, as date objects have no such values. If they’re used anyway, 0 is substituted for them.

      The full set of format codes supported varies across platforms, because Python calls the platform C library’s strftime() function, and platform variations are common. To see the full set of format codes supported on your platform, consult the strftime(3) documentation.

      The following is a list of all the format codes that the C standard (1989 version) requires, and these work on all platforms with a standard C implementation. Note that the 1999 version of the C standard added additional format codes.

      datetime — Basic date and time types¶

      The datetime module supplies classes for manipulating dates and times.

      While date and time arithmetic is supported, the focus of the implementation is on efficient attribute extraction for output formatting and manipulation.

      General calendar related functions.

      Time access and conversions.

      Concrete time zones representing the IANA time zone database.

      Third-party library with expanded time zone and parsing support.

      Aware and Naive Objects¶

      Date and time objects may be categorized as “aware” or “naive” depending on whether or not they include timezone information.

      With sufficient knowledge of applicable algorithmic and political time adjustments, such as time zone and daylight saving time information, an aware object can locate itself relative to other aware objects. An aware object represents a specific moment in time that is not open to interpretation. 1

      A naive object does not contain enough information to unambiguously locate itself relative to other date/time objects. Whether a naive object represents Coordinated Universal Time (UTC), local time, or time in some other timezone is purely up to the program, just like it is up to the program whether a particular number represents metres, miles, or mass. Naive objects are easy to understand and to work with, at the cost of ignoring some aspects of reality.

      For applications requiring aware objects, datetime and time objects have an optional time zone information attribute, tzinfo , that can be set to an instance of a subclass of the abstract tzinfo class. These tzinfo objects capture information about the offset from UTC time, the time zone name, and whether daylight saving time is in effect.

      Only one concrete tzinfo class, the timezone class, is supplied by the datetime module. The timezone class can represent simple timezones with fixed offsets from UTC, such as UTC itself or North American EST and EDT timezones. Supporting timezones at deeper levels of detail is up to the application. The rules for time adjustment across the world are more political than rational, change frequently, and there is no standard suitable for every application aside from UTC.

      Constants¶

      The datetime module exports the following constants:

      The smallest year number allowed in a date or datetime object. MINYEAR is 1 .

      The largest year number allowed in a date or datetime object. MAXYEAR is 9999 .

      Alias for the UTC timezone singleton datetime.timezone.utc .

      New in version 3.11.

      Available Types¶

      An idealized naive date, assuming the current Gregorian calendar always was, and always will be, in effect. Attributes: year , month , and day .

      class datetime. time

      An idealized time, independent of any particular day, assuming that every day has exactly 24*60*60 seconds. (There is no notion of “leap seconds” here.) Attributes: hour , minute , second , microsecond , and tzinfo .

      class datetime. datetime

      A combination of a date and a time. Attributes: year , month , day , hour , minute , second , microsecond , and tzinfo .

      class datetime. timedelta

      A duration expressing the difference between two date , time , or datetime instances to microsecond resolution.

      class datetime. tzinfo

      An abstract base class for time zone information objects. These are used by the datetime and time classes to provide a customizable notion of time adjustment (for example, to account for time zone and/or daylight saving time).

      class datetime. timezone

      A class that implements the tzinfo abstract base class as a fixed offset from the UTC.

      New in version 3.2.

      Objects of these types are immutable.

      Common Properties¶

      The date , datetime , time , and timezone types share these common features:

      Objects of these types are immutable.

      Objects of these types are hashable , meaning that they can be used as dictionary keys.

      Objects of these types support efficient pickling via the pickle module.

      Determining if an Object is Aware or Naive¶

      Objects of the date type are always naive.

      An object of type time or datetime may be aware or naive.

      A datetime object d is aware if both of the following hold:

      d.tzinfo is not None

      d.tzinfo.utcoffset(d) does not return None

      Otherwise, d is naive.

      A time object t is aware if both of the following hold:

      t.tzinfo is not None

      t.tzinfo.utcoffset(None) does not return None .

      Otherwise, t is naive.

      The distinction between aware and naive doesn’t apply to timedelta objects.

      timedelta Objects¶

      A timedelta object represents a duration, the difference between two dates or times.

      class datetime. timedelta ( days = 0 , seconds = 0 , microseconds = 0 , milliseconds = 0 , minutes = 0 , hours = 0 , weeks = 0 ) ¶

      All arguments are optional and default to 0 . Arguments may be integers or floats, and may be positive or negative.

      Only days, seconds and microseconds are stored internally. Arguments are converted to those units:

      A millisecond is converted to 1000 microseconds.

      A minute is converted to 60 seconds.

      An hour is converted to 3600 seconds.

      A week is converted to 7 days.

      and days, seconds and microseconds are then normalized so that the representation is unique, with

      0 <= microseconds < 1000000

      0 <= seconds < 3600*24 (the number of seconds in one day)

      -999999999 <= days <= 999999999

      The following example illustrates how any arguments besides days, seconds and microseconds are “merged” and normalized into those three resulting attributes:

      If any argument is a float and there are fractional microseconds, the fractional microseconds left over from all arguments are combined and their sum is rounded to the nearest microsecond using round-half-to-even tiebreaker. If no argument is a float, the conversion and normalization processes are exact (no information is lost).

      If the normalized value of days lies outside the indicated range, OverflowError is raised.

      Note that normalization of negative values may be surprising at first. For example:

      The most negative timedelta object, timedelta(-999999999) .

      The most positive timedelta object, timedelta(days=999999999, hours=23, minutes=59, seconds=59, microseconds=999999) .

      The smallest possible difference between non-equal timedelta objects, timedelta(microseconds=1) .

      Note that, because of normalization, timedelta.max > -timedelta.min . -timedelta.max is not representable as a timedelta object.

      Instance attributes (read-only):

      Between -999999999 and 999999999 inclusive

      Between 0 and 86399 inclusive

      Between 0 and 999999 inclusive

      Difference of t2 and t3. Afterwards t1 == t2 — t3 and t2 == t1 + t3 are true. (1)(6)

      t1 = t2 * i or t1 = i * t2

      Delta multiplied by an integer. Afterwards t1 // i == t2 is true, provided i != 0 .

      In general, t1 * i == t1 * (i-1) + t1 is true. (1)

      t1 = t2 * f or t1 = f * t2

      Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.

      Division (3) of overall duration t2 by interval unit t3. Returns a float object.

      t1 = t2 / f or t1 = t2 / i

      Delta divided by a float or an int. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.

      t1 = t2 // i or t1 = t2 // t3

      The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)

      The remainder is computed as a timedelta object. (3)

      q, r = divmod(t1, t2)

      Computes the quotient and the remainder: q = t1 // t2 (3) and r = t1 % t2 . q is an integer and r is a timedelta object.

      Returns a timedelta object with the same value. (2)

      equivalent to timedelta (-t1.days, —t1.seconds, —t1.microseconds), and to t1* -1. (1)(4)

      equivalent to +t when t.days >= 0 , and to —t when t.days < 0 . (2)

      Returns a string in the form [D day[s], ][H]H:MM:SS[.UUUUUU] , where D is negative for negative t . (5)

      Returns a string representation of the timedelta object as a constructor call with canonical attribute values.

      This is exact but may overflow.

      This is exact and cannot overflow.

      —timedelta.max is not representable as a timedelta object.

      String representations of timedelta objects are normalized similarly to their internal representation. This leads to somewhat unusual results for negative timedeltas. For example:

      The expression t2 — t3 will always be equal to the expression t2 + (-t3) except when t3 is equal to timedelta.max ; in that case the former will produce a result while the latter will overflow.

      In addition to the operations listed above, timedelta objects support certain additions and subtractions with date and datetime objects (see below).

      Changed in version 3.2: Floor division and true division of a timedelta object by another timedelta object are now supported, as are remainder operations and the divmod() function. True division and multiplication of a timedelta object by a float object are now supported.

      Comparisons of timedelta objects are supported, with some caveats.

      The comparisons == or != always return a bool , no matter the type of the compared object:

      For all other comparisons (such as < and > ), when a timedelta object is compared to an object of a different type, TypeError is raised:

      In Boolean contexts, a timedelta object is considered to be true if and only if it isn’t equal to timedelta(0) .

      Return the total number of seconds contained in the duration. Equivalent to td / timedelta(seconds=1) . For interval units other than seconds, use the division form directly (e.g. td / timedelta(microseconds=1) ).

      Note that for very large time intervals (greater than 270 years on most platforms) this method will lose microsecond accuracy.

      New in version 3.2.

      Examples of usage: timedelta ¶

      An additional example of normalization:

      Examples of timedelta arithmetic:

      date Objects¶

      A date object represents a date (year, month and day) in an idealized calendar, the current Gregorian calendar indefinitely extended in both directions.

      January 1 of year 1 is called day number 1, January 2 of year 1 is called day number 2, and so on. 2

      All arguments are required. Arguments must be integers, in the following ranges:

      MINYEAR <= year <= MAXYEAR

      1 <= day <= number of days in the given month and year

      If an argument outside those ranges is given, ValueError is raised.

      Other constructors, all class methods:

      classmethod date. today ( ) ¶

      Return the current local date.

      This is equivalent to date.fromtimestamp(time.time()) .

      classmethod date. fromtimestamp ( timestamp ) ¶

      Return the local date corresponding to the POSIX timestamp, such as is returned by time.time() .

      This may raise OverflowError , if the timestamp is out of the range of values supported by the platform C localtime() function, and OSError on localtime() failure. It’s common for this to be restricted to years from 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp() .

      Changed in version 3.3: Raise OverflowError instead of ValueError if the timestamp is out of the range of values supported by the platform C localtime() function. Raise OSError instead of ValueError on localtime() failure.

      Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.

      ValueError is raised unless 1 <= ordinal <= date.max.toordinal() . For any date d, date.fromordinal(d.toordinal()) == d .

      classmethod date. fromisoformat ( date_string ) ¶

      Return a date corresponding to a date_string given in any valid ISO 8601 format, except ordinal dates (e.g. YYYY-DDD ):

      New in version 3.7.

      Changed in version 3.11: Previously, this method only supported the format YYYY-MM-DD .

      Return a date corresponding to the ISO calendar date specified by year, week and day. This is the inverse of the function date.isocalendar() .

      New in version 3.8.

      The earliest representable date, date(MINYEAR, 1, 1) .

      The latest representable date, date(MAXYEAR, 12, 31) .

      The smallest possible difference between non-equal date objects, timedelta(days=1) .

      Instance attributes (read-only):

      Between MINYEAR and MAXYEAR inclusive.

      Between 1 and 12 inclusive.

      Between 1 and the number of days in the given month of the given year.

      date2 = date1 + timedelta

      date2 will be timedelta.days days after date1. (1)

      date2 = date1 — timedelta

      Computes date2 such that date2 + timedelta == date1 . (2)

      timedelta = date1 — date2

      date1 is considered less than date2 when date1 precedes date2 in time. (4)

      date2 is moved forward in time if timedelta.days > 0 , or backward if timedelta.days < 0 . Afterward date2 — date1 == timedelta.days . timedelta.seconds and timedelta.microseconds are ignored. OverflowError is raised if date2.year would be smaller than MINYEAR or larger than MAXYEAR .

      timedelta.seconds and timedelta.microseconds are ignored.

      This is exact, and cannot overflow. timedelta.seconds and timedelta.microseconds are 0, and date2 + timedelta == date1 after.

      In other words, date1 < date2 if and only if date1.toordinal() < date2.toordinal() . Date comparison raises TypeError if the other comparand isn’t also a date object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a date object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      In Boolean contexts, all date objects are considered to be true.

      date. replace ( year = self.year , month = self.month , day = self.day ) ¶

      Return a date with the same value, except for those parameters given new values by whichever keyword arguments are specified.

      The hours, minutes and seconds are 0, and the DST flag is -1.

      d.timetuple() is equivalent to:

      where yday = d.toordinal() — date(d.year, 1, 1).toordinal() + 1 is the day number within the current year starting with 1 for January 1st.

      Return the proleptic Gregorian ordinal of the date, where January 1 of year 1 has ordinal 1. For any date object d, date.fromordinal(d.toordinal()) == d .

      Return the day of the week as an integer, where Monday is 0 and Sunday is 6. For example, date(2002, 12, 4).weekday() == 2 , a Wednesday. See also isoweekday() .

      Return the day of the week as an integer, where Monday is 1 and Sunday is 7. For example, date(2002, 12, 4).isoweekday() == 3 , a Wednesday. See also weekday() , isocalendar() .

      Return a named tuple object with three components: year , week and weekday .

      The ISO calendar is a widely used variant of the Gregorian calendar. 3

      The ISO year consists of 52 or 53 full weeks, and where a week starts on a Monday and ends on a Sunday. The first week of an ISO year is the first (Gregorian) calendar week of a year containing a Thursday. This is called week number 1, and the ISO year of that Thursday is the same as its Gregorian year.

      For example, 2004 begins on a Thursday, so the first week of ISO year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan 2004:

      Changed in version 3.9: Result changed from a tuple to a named tuple .

      Return a string representing the date in ISO 8601 format, YYYY-MM-DD :

      For a date d, str(d) is equivalent to d.isoformat() .

      Return a string representing the date:

      d.ctime() is equivalent to:

      on platforms where the native C ctime() function (which time.ctime() invokes, but which date.ctime() does not invoke) conforms to the C standard.

      date. strftime ( format ) ¶

      Return a string representing the date, controlled by an explicit format string. Format codes referring to hours, minutes or seconds will see 0 values. See also strftime() and strptime() Behavior and date.isoformat() .

      date. __format__ ( format ) ¶

      Same as date.strftime() . This makes it possible to specify a format string for a date object in formatted string literals and when using str.format() . See also strftime() and strptime() Behavior and date.isoformat() .

      Examples of Usage: date ¶

      Example of counting days to an event:

      More examples of working with date :

      datetime Objects¶

      A datetime object is a single object containing all the information from a date object and a time object.

      Like a date object, datetime assumes the current Gregorian calendar extended in both directions; like a time object, datetime assumes there are exactly 3600*24 seconds in every day.

      class datetime. datetime ( year , month , day , hour = 0 , minute = 0 , second = 0 , microsecond = 0 , tzinfo = None , * , fold = 0 ) ¶

      The year, month and day arguments are required. tzinfo may be None , or an instance of a tzinfo subclass. The remaining arguments must be integers in the following ranges:

      MINYEAR <= year <= MAXYEAR ,

      1 <= day <= number of days in the given month and year ,

      0 <= microsecond < 1000000 ,

      If an argument outside those ranges is given, ValueError is raised.

      New in version 3.6: Added the fold argument.

      Other constructors, all class methods:

      classmethod datetime. today ( ) ¶

      Return the current local datetime, with tzinfo None .

      This method is functionally equivalent to now() , but without a tz parameter.

      classmethod datetime. now ( tz = None ) ¶

      Return the current local date and time.

      If optional argument tz is None or not specified, this is like today() , but, if possible, supplies more precision than can be gotten from going through a time.time() timestamp (for example, this may be possible on platforms supplying the C gettimeofday() function).

      If tz is not None , it must be an instance of a tzinfo subclass, and the current date and time are converted to tz’s time zone.

      This function is preferred over today() and utcnow() .

      classmethod datetime. utcnow ( ) ¶

      Return the current UTC date and time, with tzinfo None .

      This is like now() , but returns the current UTC date and time, as a naive datetime object. An aware current UTC datetime can be obtained by calling datetime.now(timezone.utc) . See also now() .

      Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing the current time in UTC is by calling datetime.now(timezone.utc) .

      Return the local date and time corresponding to the POSIX timestamp, such as is returned by time.time() . If optional argument tz is None or not specified, the timestamp is converted to the platform’s local date and time, and the returned datetime object is naive.

      If tz is not None , it must be an instance of a tzinfo subclass, and the timestamp is converted to tz’s time zone.

      fromtimestamp() may raise OverflowError , if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions, and OSError on localtime() or gmtime() failure. It’s common for this to be restricted to years in 1970 through 2038. Note that on non-POSIX systems that include leap seconds in their notion of a timestamp, leap seconds are ignored by fromtimestamp() , and then it’s possible to have two timestamps differing by a second that yield identical datetime objects. This method is preferred over utcfromtimestamp() .

      Changed in version 3.3: Raise OverflowError instead of ValueError if the timestamp is out of the range of values supported by the platform C localtime() or gmtime() functions. Raise OSError instead of ValueError on localtime() or gmtime() failure.

      Changed in version 3.6: fromtimestamp() may return instances with fold set to 1.

      Return the UTC datetime corresponding to the POSIX timestamp, with tzinfo None . (The resulting object is naive.)

      This may raise OverflowError , if the timestamp is out of the range of values supported by the platform C gmtime() function, and OSError on gmtime() failure. It’s common for this to be restricted to years in 1970 through 2038.

      To get an aware datetime object, call fromtimestamp() :

      On the POSIX compliant platforms, it is equivalent to the following expression:

      except the latter formula always supports the full years range: between MINYEAR and MAXYEAR inclusive.

      Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing a specific timestamp in UTC is by calling datetime.fromtimestamp(timestamp, tz=timezone.utc) .

      Changed in version 3.3: Raise OverflowError instead of ValueError if the timestamp is out of the range of values supported by the platform C gmtime() function. Raise OSError instead of ValueError on gmtime() failure.

      Return the datetime corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. ValueError is raised unless 1 <= ordinal <= datetime.max.toordinal() . The hour, minute, second and microsecond of the result are all 0, and tzinfo is None .

      classmethod datetime. combine ( date , time , tzinfo = self.tzinfo ) ¶

      Return a new datetime object whose date components are equal to the given date object’s, and whose time components are equal to the given time object’s. If the tzinfo argument is provided, its value is used to set the tzinfo attribute of the result, otherwise the tzinfo attribute of the time argument is used.

      For any datetime object d, d == datetime.combine(d.date(), d.time(), d.tzinfo) . If date is a datetime object, its time components and tzinfo attributes are ignored.

      Changed in version 3.6: Added the tzinfo argument.

      Return a datetime corresponding to a date_string in any valid ISO 8601 format, with the following exceptions:

      Time zone offsets may have fractional seconds.

      The T separator may be replaced by any single unicode character.

      Ordinal dates are not currently supported.

      Fractional hours and minutes are not supported.

      New in version 3.7.

      Changed in version 3.11: Previously, this method only supported formats that could be emitted by date.isoformat() or datetime.isoformat() .

      Return a datetime corresponding to the ISO calendar date specified by year, week and day. The non-date components of the datetime are populated with their normal default values. This is the inverse of the function datetime.isocalendar() .

      New in version 3.8.

      Return a datetime corresponding to date_string, parsed according to format.

      If format does not contain microseconds or timezone information, this is equivalent to:

      ValueError is raised if the date_string and format can’t be parsed by time.strptime() or if it returns a value which isn’t a time tuple. See also strftime() and strptime() Behavior and datetime.fromisoformat() .

      The earliest representable datetime , datetime(MINYEAR, 1, 1, tzinfo=None) .

      The latest representable datetime , datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999, tzinfo=None) .

      The smallest possible difference between non-equal datetime objects, timedelta(microseconds=1) .

      Instance attributes (read-only):

      Between MINYEAR and MAXYEAR inclusive.

      Between 1 and 12 inclusive.

      Between 1 and the number of days in the given month of the given year.

      The object passed as the tzinfo argument to the datetime constructor, or None if none was passed.

      In [0, 1] . Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The value 0 (1) represents the earlier (later) of the two moments with the same wall time representation.

      New in version 3.6.

      datetime2 = datetime1 + timedelta

      datetime2 = datetime1 — timedelta

      timedelta = datetime1 — datetime2

      datetime2 is a duration of timedelta removed from datetime1, moving forward in time if timedelta.days > 0, or backward if timedelta.days < 0. The result has the same tzinfo attribute as the input datetime, and datetime2 — datetime1 == timedelta after. OverflowError is raised if datetime2.year would be smaller than MINYEAR or larger than MAXYEAR . Note that no time zone adjustments are done even if the input is an aware object.

      Computes the datetime2 such that datetime2 + timedelta == datetime1. As for addition, the result has the same tzinfo attribute as the input datetime, and no time zone adjustments are done even if the input is aware.

      Subtraction of a datetime from a datetime is defined only if both operands are naive, or if both are aware. If one is aware and the other is naive, TypeError is raised.

      If both are naive, or both are aware and have the same tzinfo attribute, the tzinfo attributes are ignored, and the result is a timedelta object t such that datetime2 + t == datetime1 . No time zone adjustments are done in this case.

      If both are aware and have different tzinfo attributes, a-b acts as if a and b were first converted to naive UTC datetimes first. The result is (a.replace(tzinfo=None) — a.utcoffset()) — (b.replace(tzinfo=None) — b.utcoffset()) except that the implementation never overflows.

      datetime1 is considered less than datetime2 when datetime1 precedes datetime2 in time.

      If one comparand is naive and the other is aware, TypeError is raised if an order comparison is attempted. For equality comparisons, naive instances are never equal to aware instances.

      If both comparands are aware, and have the same tzinfo attribute, the common tzinfo attribute is ignored and the base datetimes are compared. If both comparands are aware and have different tzinfo attributes, the comparands are first adjusted by subtracting their UTC offsets (obtained from self.utcoffset() ).

      Changed in version 3.3: Equality comparisons between aware and naive datetime instances don’t raise TypeError .

      In order to stop comparison from falling back to the default scheme of comparing object addresses, datetime comparison normally raises TypeError if the other comparand isn’t also a datetime object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a datetime object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      Return date object with same year, month and day.

      Return time object with same hour, minute, second, microsecond and fold. tzinfo is None . See also method timetz() .

      Changed in version 3.6: The fold value is copied to the returned time object.

      Return time object with same hour, minute, second, microsecond, fold, and tzinfo attributes. See also method time() .

      Changed in version 3.6: The fold value is copied to the returned time object.

      Return a datetime with the same attributes, except for those attributes given new values by whichever keyword arguments are specified. Note that tzinfo=None can be specified to create a naive datetime from an aware datetime with no conversion of date and time data.

      New in version 3.6: Added the fold argument.

      Return a datetime object with new tzinfo attribute tz, adjusting the date and time data so the result is the same UTC time as self, but in tz’s local time.

      If provided, tz must be an instance of a tzinfo subclass, and its utcoffset() and dst() methods must not return None . If self is naive, it is presumed to represent time in the system timezone.

      If called without arguments (or with tz=None ) the system local timezone is assumed for the target timezone. The .tzinfo attribute of the converted datetime instance will be set to an instance of timezone with the zone name and offset obtained from the OS.

      If self.tzinfo is tz, self.astimezone(tz) is equal to self: no adjustment of date or time data is performed. Else the result is local time in the timezone tz, representing the same UTC time as self: after astz = dt.astimezone(tz) , astz — astz.utcoffset() will have the same date and time data as dt — dt.utcoffset() .

      If you merely want to attach a time zone object tz to a datetime dt without adjustment of date and time data, use dt.replace(tzinfo=tz) . If you merely want to remove the time zone object from an aware datetime dt without conversion of date and time data, use dt.replace(tzinfo=None) .

      Note that the default tzinfo.fromutc() method can be overridden in a tzinfo subclass to affect the result returned by astimezone() . Ignoring error cases, astimezone() acts like:

      Changed in version 3.3: tz now can be omitted.

      Changed in version 3.6: The astimezone() method can now be called on naive instances that are presumed to represent system local time.

      If tzinfo is None , returns None , else returns self.tzinfo.utcoffset(self) , and raises an exception if the latter doesn’t return None or a timedelta object with magnitude less than one day.

      Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.

      If tzinfo is None , returns None , else returns self.tzinfo.dst(self) , and raises an exception if the latter doesn’t return None or a timedelta object with magnitude less than one day.

      Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.

      If tzinfo is None , returns None , else returns self.tzinfo.tzname(self) , raises an exception if the latter doesn’t return None or a string object,

      d.timetuple() is equivalent to:

      where yday = d.toordinal() — date(d.year, 1, 1).toordinal() + 1 is the day number within the current year starting with 1 for January 1st. The tm_isdst flag of the result is set according to the dst() method: tzinfo is None or dst() returns None , tm_isdst is set to -1 ; else if dst() returns a non-zero value, tm_isdst is set to 1 ; else tm_isdst is set to 0 .

      If datetime instance d is naive, this is the same as d.timetuple() except that tm_isdst is forced to 0 regardless of what d.dst() returns. DST is never in effect for a UTC time.

      If d is aware, d is normalized to UTC time, by subtracting d.utcoffset() , and a time.struct_time for the normalized time is returned. tm_isdst is forced to 0. Note that an OverflowError may be raised if d.year was MINYEAR or MAXYEAR and UTC adjustment spills over a year boundary.

      Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC; as a result, using datetime.utctimetuple() may give misleading results. If you have a naive datetime representing UTC, use datetime.replace(tzinfo=timezone.utc) to make it aware, at which point you can use datetime.timetuple() .

      Return the proleptic Gregorian ordinal of the date. The same as self.date().toordinal() .

      Return POSIX timestamp corresponding to the datetime instance. The return value is a float similar to that returned by time.time() .

      Naive datetime instances are assumed to represent local time and this method relies on the platform C mktime() function to perform the conversion. Since datetime supports wider range of values than mktime() on many platforms, this method may raise OverflowError for times far in the past or far in the future.

      For aware datetime instances, the return value is computed as:

      New in version 3.3.

      Changed in version 3.6: The timestamp() method uses the fold attribute to disambiguate the times during a repeated interval.

      There is no method to obtain the POSIX timestamp directly from a naive datetime instance representing UTC time. If your application uses this convention and your system timezone is not set to UTC, you can obtain the POSIX timestamp by supplying tzinfo=timezone.utc :

      or by calculating the timestamp directly:

      Return the day of the week as an integer, where Monday is 0 and Sunday is 6. The same as self.date().weekday() . See also isoweekday() .

      Return the day of the week as an integer, where Monday is 1 and Sunday is 7. The same as self.date().isoweekday() . See also weekday() , isocalendar() .

      Return a named tuple with three components: year , week and weekday . The same as self.date().isocalendar() .

      datetime. isoformat ( sep = ‘T’ , timespec = ‘auto’ ) ¶

      Return a string representing the date and time in ISO 8601 format:

      YYYY-MM-DDTHH:MM:SS.ffffff , if microsecond is not 0

      YYYY-MM-DDTHH:MM:SS , if microsecond is 0

      If utcoffset() does not return None , a string is appended, giving the UTC offset:

      YYYY-MM-DDTHH:MM:SS.ffffff+HH:MM[:SS[.ffffff]] , if microsecond is not 0

      YYYY-MM-DDTHH:MM:SS+HH:MM[:SS[.ffffff]] , if microsecond is 0

      The optional argument sep (default ‘T’ ) is a one-character separator, placed between the date and time portions of the result. For example:

      The optional argument timespec specifies the number of additional components of the time to include (the default is ‘auto’ ). It can be one of the following:

      ‘auto’ : Same as ‘seconds’ if microsecond is 0, same as ‘microseconds’ otherwise.

      ‘hours’ : Include the hour in the two-digit HH format.

      ‘minutes’ : Include hour and minute in HH:MM format.

      ‘seconds’ : Include hour , minute , and second in HH:MM:SS format.

      ‘milliseconds’ : Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.

      ‘microseconds’ : Include full time in HH:MM:SS.ffffff format.

      Excluded time components are truncated, not rounded.

      ValueError will be raised on an invalid timespec argument:

      New in version 3.6: Added the timespec argument.

      For a datetime instance d, str(d) is equivalent to d.isoformat(‘ ‘) .

      Return a string representing the date and time:

      The output string will not include time zone information, regardless of whether the input is aware or naive.

      d.ctime() is equivalent to:

      on platforms where the native C ctime() function (which time.ctime() invokes, but which datetime.ctime() does not invoke) conforms to the C standard.

      datetime. strftime ( format ) ¶

      Return a string representing the date and time, controlled by an explicit format string. See also strftime() and strptime() Behavior and datetime.isoformat() .

      datetime. __format__ ( format ) ¶

      Same as datetime.strftime() . This makes it possible to specify a format string for a datetime object in formatted string literals and when using str.format() . See also strftime() and strptime() Behavior and datetime.isoformat() .

      Examples of Usage: datetime ¶

      Examples of working with datetime objects:

      The example below defines a tzinfo subclass capturing time zone information for Kabul, Afghanistan, which used +4 UTC until 1945 and then +4:30 UTC thereafter:

      Usage of KabulTz from above:

      time Objects¶

      A time object represents a (local) time of day, independent of any particular day, and subject to adjustment via a tzinfo object.

      class datetime. time ( hour = 0 , minute = 0 , second = 0 , microsecond = 0 , tzinfo = None , * , fold = 0 ) ¶

      All arguments are optional. tzinfo may be None , or an instance of a tzinfo subclass. The remaining arguments must be integers in the following ranges:

      0 <= microsecond < 1000000 ,

      If an argument outside those ranges is given, ValueError is raised. All default to 0 except tzinfo, which defaults to None .

      The earliest representable time , time(0, 0, 0, 0) .

      The latest representable time , time(23, 59, 59, 999999) .

      The smallest possible difference between non-equal time objects, timedelta(microseconds=1) , although note that arithmetic on time objects is not supported.

      Instance attributes (read-only):

      The object passed as the tzinfo argument to the time constructor, or None if none was passed.

      In [0, 1] . Used to disambiguate wall times during a repeated interval. (A repeated interval occurs when clocks are rolled back at the end of daylight saving time or when the UTC offset for the current zone is decreased for political reasons.) The value 0 (1) represents the earlier (later) of the two moments with the same wall time representation.

      New in version 3.6.

      time objects support comparison of time to time , where a is considered less than b when a precedes b in time. If one comparand is naive and the other is aware, TypeError is raised if an order comparison is attempted. For equality comparisons, naive instances are never equal to aware instances.

      If both comparands are aware, and have the same tzinfo attribute, the common tzinfo attribute is ignored and the base times are compared. If both comparands are aware and have different tzinfo attributes, the comparands are first adjusted by subtracting their UTC offsets (obtained from self.utcoffset() ). In order to stop mixed-type comparisons from falling back to the default comparison by object address, when a time object is compared to an object of a different type, TypeError is raised unless the comparison is == or != . The latter cases return False or True , respectively.

      Changed in version 3.3: Equality comparisons between aware and naive time instances don’t raise TypeError .

      In Boolean contexts, a time object is always considered to be true.

      Changed in version 3.5: Before Python 3.5, a time object was considered to be false if it represented midnight in UTC. This behavior was considered obscure and error-prone and has been removed in Python 3.5. See bpo-13936 for full details.

      classmethod time. fromisoformat ( time_string ) ¶

      Return a time corresponding to a time_string in any valid ISO 8601 format, with the following exceptions:

      Time zone offsets may have fractional seconds.

      The leading T , normally required in cases where there may be ambiguity between a date and a time, is not required.

      Fractional seconds may have any number of digits (anything beyond 6 will be truncated).

      Fractional hours and minutes are not supported.

      New in version 3.7.

      Changed in version 3.11: Previously, this method only supported formats that could be emitted by time.isoformat() .

      time. replace ( hour = self.hour , minute = self.minute , second = self.second , microsecond = self.microsecond , tzinfo = self.tzinfo , * , fold = 0 ) ¶

      Return a time with the same value, except for those attributes given new values by whichever keyword arguments are specified. Note that tzinfo=None can be specified to create a naive time from an aware time , without conversion of the time data.

      New in version 3.6: Added the fold argument.

      Return a string representing the time in ISO 8601 format, one of:

      HH:MM:SS.ffffff , if microsecond is not 0

      HH:MM:SS , if microsecond is 0

      HH:MM:SS.ffffff+HH:MM[:SS[.ffffff]] , if utcoffset() does not return None

      HH:MM:SS+HH:MM[:SS[.ffffff]] , if microsecond is 0 and utcoffset() does not return None

      The optional argument timespec specifies the number of additional components of the time to include (the default is ‘auto’ ). It can be one of the following:

      ‘auto’ : Same as ‘seconds’ if microsecond is 0, same as ‘microseconds’ otherwise.

      ‘hours’ : Include the hour in the two-digit HH format.

      ‘minutes’ : Include hour and minute in HH:MM format.

      ‘seconds’ : Include hour , minute , and second in HH:MM:SS format.

      ‘milliseconds’ : Include full time, but truncate fractional second part to milliseconds. HH:MM:SS.sss format.

      ‘microseconds’ : Include full time in HH:MM:SS.ffffff format.

      Excluded time components are truncated, not rounded.

      ValueError will be raised on an invalid timespec argument.

      New in version 3.6: Added the timespec argument.

      For a time t, str(t) is equivalent to t.isoformat() .

      time. strftime ( format ) ¶

      Return a string representing the time, controlled by an explicit format string. See also strftime() and strptime() Behavior and time.isoformat() .

      time. __format__ ( format ) ¶

      Same as time.strftime() . This makes it possible to specify a format string for a time object in formatted string literals and when using str.format() . See also strftime() and strptime() Behavior and time.isoformat() .

      If tzinfo is None , returns None , else returns self.tzinfo.utcoffset(None) , and raises an exception if the latter doesn’t return None or a timedelta object with magnitude less than one day.

      Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.

      If tzinfo is None , returns None , else returns self.tzinfo.dst(None) , and raises an exception if the latter doesn’t return None , or a timedelta object with magnitude less than one day.

      Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.

      If tzinfo is None , returns None , else returns self.tzinfo.tzname(None) , or raises an exception if the latter doesn’t return None or a string object.

      Examples of Usage: time ¶

      Examples of working with a time object:

      tzinfo Objects¶

      This is an abstract base class, meaning that this class should not be instantiated directly. Define a subclass of tzinfo to capture information about a particular time zone.

      An instance of (a concrete subclass of) tzinfo can be passed to the constructors for datetime and time objects. The latter objects view their attributes as being in local time, and the tzinfo object supports methods revealing offset of local time from UTC, the name of the time zone, and DST offset, all relative to a date or time object passed to them.

      You need to derive a concrete subclass, and (at least) supply implementations of the standard tzinfo methods needed by the datetime methods you use. The datetime module provides timezone , a simple concrete subclass of tzinfo which can represent timezones with fixed offset from UTC such as UTC itself or North American EST and EDT.

      Special requirement for pickling: A tzinfo subclass must have an __init__() method that can be called with no arguments, otherwise it can be pickled but possibly not unpickled again. This is a technical requirement that may be relaxed in the future.

      A concrete subclass of tzinfo may need to implement the following methods. Exactly which methods are needed depends on the uses made of aware datetime objects. If in doubt, simply implement all of them.

      tzinfo. utcoffset ( dt ) ¶

      Return offset of local time from UTC, as a timedelta object that is positive east of UTC. If local time is west of UTC, this should be negative.

      This represents the total offset from UTC; for example, if a tzinfo object represents both time zone and DST adjustments, utcoffset() should return their sum. If the UTC offset isn’t known, return None . Else the value returned must be a timedelta object strictly between -timedelta(hours=24) and timedelta(hours=24) (the magnitude of the offset must be less than one day). Most implementations of utcoffset() will probably look like one of these two:

      If utcoffset() does not return None , dst() should not return None either.

      The default implementation of utcoffset() raises NotImplementedError .

      Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.

      Return the daylight saving time (DST) adjustment, as a timedelta object or None if DST information isn’t known.

      Return timedelta(0) if DST is not in effect. If DST is in effect, return the offset as a timedelta object (see utcoffset() for details). Note that DST offset, if applicable, has already been added to the UTC offset returned by utcoffset() , so there’s no need to consult dst() unless you’re interested in obtaining DST info separately. For example, datetime.timetuple() calls its tzinfo attribute’s dst() method to determine how the tm_isdst flag should be set, and tzinfo.fromutc() calls dst() to account for DST changes when crossing time zones.

      An instance tz of a tzinfo subclass that models both standard and daylight times must be consistent in this sense:

      must return the same result for every datetime dt with dt.tzinfo == tz For sane tzinfo subclasses, this expression yields the time zone’s “standard offset”, which should not depend on the date or the time, but only on geographic location. The implementation of datetime.astimezone() relies on this, but cannot detect violations; it’s the programmer’s responsibility to ensure it. If a tzinfo subclass cannot guarantee this, it may be able to override the default implementation of tzinfo.fromutc() to work correctly with astimezone() regardless.

      Most implementations of dst() will probably look like one of these two:

      The default implementation of dst() raises NotImplementedError .

      Changed in version 3.7: The DST offset is not restricted to a whole number of minutes.

      Return the time zone name corresponding to the datetime object dt, as a string. Nothing about string names is defined by the datetime module, and there’s no requirement that it mean anything in particular. For example, “GMT”, “UTC”, “-500”, “-5:00”, “EDT”, “US/Eastern”, “America/New York” are all valid replies. Return None if a string name isn’t known. Note that this is a method rather than a fixed string primarily because some tzinfo subclasses will wish to return different names depending on the specific value of dt passed, especially if the tzinfo class is accounting for daylight time.

      The default implementation of tzname() raises NotImplementedError .

      These methods are called by a datetime or time object, in response to their methods of the same names. A datetime object passes itself as the argument, and a time object passes None as the argument. A tzinfo subclass’s methods should therefore be prepared to accept a dt argument of None , or of class datetime .

      When None is passed, it’s up to the class designer to decide the best response. For example, returning None is appropriate if the class wishes to say that time objects don’t participate in the tzinfo protocols. It may be more useful for utcoffset(None) to return the standard UTC offset, as there is no other convention for discovering the standard offset.

      When a datetime object is passed in response to a datetime method, dt.tzinfo is the same object as self. tzinfo methods can rely on this, unless user code calls tzinfo methods directly. The intent is that the tzinfo methods interpret dt as being in local time, and not need worry about objects in other timezones.

      There is one more tzinfo method that a subclass may wish to override:

      tzinfo. fromutc ( dt ) ¶

      This is called from the default datetime.astimezone() implementation. When called from that, dt.tzinfo is self, and dt’s date and time data are to be viewed as expressing a UTC time. The purpose of fromutc() is to adjust the date and time data, returning an equivalent datetime in self’s local time.

      Most tzinfo subclasses should be able to inherit the default fromutc() implementation without problems. It’s strong enough to handle fixed-offset time zones, and time zones accounting for both standard and daylight time, and the latter even if the DST transition times differ in different years. An example of a time zone the default fromutc() implementation may not handle correctly in all cases is one where the standard offset (from UTC) depends on the specific date and time passed, which can happen for political reasons. The default implementations of astimezone() and fromutc() may not produce the result you want if the result is one of the hours straddling the moment the standard offset changes.

      Skipping code for error cases, the default fromutc() implementation acts like:

      In the following tzinfo_examples.py file there are some examples of tzinfo classes:

      Note that there are unavoidable subtleties twice per year in a tzinfo subclass accounting for both standard and daylight time, at the DST transition points. For concreteness, consider US Eastern (UTC -0500), where EDT begins the minute after 1:59 (EST) on the second Sunday in March, and ends the minute after 1:59 (EDT) on the first Sunday in November:

      When DST starts (the “start” line), the local wall clock leaps from 1:59 to 3:00. A wall time of the form 2:MM doesn’t really make sense on that day, so astimezone(Eastern) won’t deliver a result with hour == 2 on the day DST begins. For example, at the Spring forward transition of 2016, we get:

      When DST ends (the “end” line), there’s a potentially worse problem: there’s an hour that can’t be spelled unambiguously in local wall time: the last hour of daylight time. In Eastern, that’s times of the form 5:MM UTC on the day daylight time ends. The local wall clock leaps from 1:59 (daylight time) back to 1:00 (standard time) again. Local times of the form 1:MM are ambiguous. astimezone() mimics the local clock’s behavior by mapping two adjacent UTC hours into the same local hour then. In the Eastern example, UTC times of the form 5:MM and 6:MM both map to 1:MM when converted to Eastern, but earlier times have the fold attribute set to 0 and the later times have it set to 1. For example, at the Fall back transition of 2016, we get:

      Note that the datetime instances that differ only by the value of the fold attribute are considered equal in comparisons.

      Applications that can’t bear wall-time ambiguities should explicitly check the value of the fold attribute or avoid using hybrid tzinfo subclasses; there are no ambiguities when using timezone , or any other fixed-offset tzinfo subclass (such as a class representing only EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)).

      zoneinfo

      The datetime module has a basic timezone class (for handling arbitrary fixed offsets from UTC) and its timezone.utc attribute (a UTC timezone instance).

      zoneinfo brings the IANA timezone database (also known as the Olson database) to Python, and its usage is recommended.

      The Time Zone Database (often called tz, tzdata or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.

      timezone Objects¶

      The timezone class is a subclass of tzinfo , each instance of which represents a timezone defined by a fixed offset from UTC.

      Objects of this class cannot be used to represent timezone information in the locations where different offsets are used in different days of the year or where historical changes have been made to civil time.

      class datetime. timezone ( offset , name = None ) ¶

      The offset argument must be specified as a timedelta object representing the difference between the local time and UTC. It must be strictly between -timedelta(hours=24) and timedelta(hours=24) , otherwise ValueError is raised.

      The name argument is optional. If specified it must be a string that will be used as the value returned by the datetime.tzname() method.

      New in version 3.2.

      Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.

      Return the fixed value specified when the timezone instance is constructed.

      The dt argument is ignored. The return value is a timedelta instance equal to the difference between the local time and UTC.

      Changed in version 3.7: The UTC offset is not restricted to a whole number of minutes.

      Return the fixed value specified when the timezone instance is constructed.

      If name is not provided in the constructor, the name returned by tzname(dt) is generated from the value of the offset as follows. If offset is timedelta(0) , the name is “UTC”, otherwise it is a string in the format UTC±HH:MM , where ± is the sign of offset , HH and MM are two digits of offset.hours and offset.minutes respectively.

      Changed in version 3.6: Name generated from offset=timedelta(0) is now plain ‘UTC’ , not ‘UTC+00:00’ .

      Always returns None .

      timezone. fromutc ( dt ) ¶

      Return dt + offset . The dt argument must be an aware datetime instance, with tzinfo set to self .

      The UTC timezone, timezone(timedelta(0)) .

      strftime() and strptime() Behavior¶

      date , datetime , and time objects all support a strftime(format) method, to create a string representing the time under the control of an explicit format string.

      Conversely, the datetime.strptime() class method creates a datetime object from a string representing a date and time and a corresponding format string.

      The table below provides a high-level comparison of strftime() versus strptime() :

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