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Timestamp Python

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Last Updated: 22 October 2020

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General | Latest Info

Dealing With Dates and Times in Python can be a hassle. Thankfully, there is a build - in way of making it easier: Python datetime module. Datetime helps us identify and process time - related elements like dates, hours, minutes, seconds, days of week, months, years, etc. It offers various services like managing time zones and daylight savings time. It can work with timestamp data. It can extract day of week, day of month, and other date and time formats from strings. In short, it is a really powerful way of handling anything date and time related in Python. So let's get into it! In this tutorial, you learn about Python datetime functions in detail, including: creating Date Objects Getting years and months from Date Getting months, days and Weekdays from Date Getting hours and minutes from Date Getting Weeks number of year from Date Converting Date object into timestamp Converting UNIX timestamp string to Date object Handling timedelta Objects Getting difference between two Dates and Times Formatting Dates: strftime and strptime Handling timezones Working With Pandas datetime Objects Getting year, month, day, hour, and minute Getting Weekday and day of year Converting Date Objects into DataFrame index as you Work through this tutorial, wed encourage you to run code on your own machine. Alternatively, if you like to run code in your browser and learn in an interactive fashion with answer - checking to be sure you are getting it right, our Python intermediate course has lessons on datetime in Python that we recommend. You can start learning by signing up for a free user account. We can see from the results above that datetime_object is indeed datetime object of datetime class. This includes year, month, day, hour, minute, second, and microsecond. Note that strptime takes two arguments: string and% y -% m -% d, another string that tells strptime how to interpret input string my_string.% Y, for example, tell it to expect the first four characters of string to be year. A full list of these patterns is available in the documentation, and well go into these methods in more depth later in this tutorial. You may also have noticed that time of 00: 00: 00pm has been added to the date. That is because we create a datetime object, which must include date and time. 00: 00: 00 is the default time that will be assigned if no time is designated in string were inputting. Anyway, we were hoping to separate out specific elements of date for our analysis. One way can do that is using build - in class attributes of datetime object, like. Month or. Year: now we can see that Python starts weeks on Monday and counts from index 0 rather than starting at 1. So it makes sense that number 3 is converted to Thursday as we saw above. Note that in the ISO calendar, week starts counting from 1, so here 5 represent the correct day of week: Friday.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Aware and Naive Objects A

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Aware datetime object embed timezone information. Rules of thumb For timezone in Python: always work with offset - aware datetime objects. Always store datetime in UTC and do timezone conversion only when interacting with users. Always use ISO 8601 as the input and output string format. There are two useful methods: pytz. Utc. Localize For converting naive datetime to timezone be offset - aware, and aware_dt. Astimezonepytz. Timezone For adjusting timezones of offset - aware objects. You should avoid naive_dt. Astimezone, which would converted to aware datetime As system timezone then converted to some_tzinfo timezone. For working with PYTZ, it is recommended to call Tz. Localize instead of naive_dt. Replace. Dt. Replace do not handle daylight savings time correctly.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Supported operations:

OperationResult
t1 = t2 + t3Sum of t2 and t3 . Afterwards t1 - t2 == t3 and t1 - t3 == t2 are true. (1)
t1 = t2 - t3Difference of t2 and t3 . Afterwards t1 == t2 - t3 and t2 == t1 + t3 are true. (1)
t1 = t2 i or t1 = i t2Delta 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 t2Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
f = t2 / t3Division (3) of t2 by t3 . Returns a float object.
t1 = t2 / f or t1 = t2 / iDelta 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 // t3The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
t1 = t2 % t3The 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.
+t1Returns a timedelta object with the same value. (2)
-t1equivalent 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 , H:MM:SS , where D is negative for negative t . (5)
repr(t)Returns a string in the form datetime.timedelta(D) , where D is negative for negative t . (5)

Table

DirectiveMeaningExampleNotes
%aWeekday as locales abbreviated name.Sun, Mon, ..., Sat (en_US); So, Mo, ..., Sa (de_DE)(1)
%AWeekday as locales full name.Sunday, Monday, ..., Saturday (en_US); Sonntag, Montag, ..., Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, ..., 6
%dDay of the month as a zero-padded decimal number.01, 02, ..., 31
%bMonth as locales abbreviated name.Jan, Feb, ..., Dec (en_US); Jan, Feb, ..., Dez (de_DE)(1)
%BMonth as locales full name.January, February, ..., December (en_US); Januar, Februar, ..., Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, ..., 12
%yYear without century as a zero-padded decimal number.00, 01, ..., 99
%YYear with century as a decimal number.0001, 0002, ..., 2013, 2014, ..., 9998, 9999(2)
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, ..., 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, ..., 12
%pLocales equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (3)
%MMinute as a zero-padded decimal number.00, 01, ..., 59
%SSecond as a zero-padded decimal number.00, 01, ..., 59(4)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, ..., 999999(5)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(6)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, ..., 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, ..., 53(7)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, ..., 53(7)
%cLocales appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocales appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocales appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

timedelta Objects A

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Date, datetime, and Time objects all support the strftime method, to create a string representing Time under control of explicit format string. Broadly speaking, dstrftime acts like Time moduleas Time. Strftimefmt, dtimetuple although not all objects support the timetuple method. Conversely, datetime. The Strptime class method creates a datetime object from string representing date and time and corresponding format string. Datetime. Strptime is equivalent to datetime * Time. Strptime, except when format includes sub - second components or timezone offset information, which are supported in datetime. Strptime but is discarded by Time. Strptime. For time objects, format codes for year,s month,ss and days should not be used as time objects have no such values. If they used anyway, 1900 is substitute for year, and 1 for month and day. For date objects, format codes for hours, minutes, seconds, and microseconds should not be used as date objects have no such values. If they are used anyway, 0 is a substitute for them. The full set of format codes support varies across platforms, because Python Call platform C libraryas strftime function, and platform variations are common. To see the full set of format codes supported on your platform, consult strftime documentation. For the same reason, handling of format strings containing Unicode code points that ca be represented in charset of current locale is also platform - dependent. On some platforms, such code points are preserve intact in output, while on others, strftime may raise UnicodeError or return empty string instead. The following is a list of all format codes that C standards require, and these work on all platforms with standard C implementation. Note that the 1999 version of C standard added additional format codes. The exact range of years for which strftime work also varies across platforms. Regardless of platform, years before 1900 cannot be used Because format depends on current locale, care should be taken when making assumptions about output value. Field orderings will vary, and output may contain Unicode characters encoded using localeas default encoding. When used with the strptime method,% p directive only affects output hour field if the% I directive is used to parse hour.S Unlike the time module, datetime module does not support leap seconds.% F is extension to set of format characters in C standard. When used with the strptime method,% f directive accepts from one to six digits and zero pads on right. New in version 2. 6 For naive object,% Z and% Z format codes are replaced by empty strings. For awareness object:% Z utcoffset is transformed into a 5 - character string of form + HHMM or - HHMM, where HH is a 2 - digit string giving the number of UTC offset hours, and MM is a 2 - digit string giving the number of UTC offset minutes. For example, if utcoffset returns to Timedelta,% Z is replaced with string - 0330.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Supported operations:

OperationResult
t1 = t2 + t3Sum of t2 and t3 . Afterwards t1 - t2 == t3 and t1 - t3 == t2 are true. (1)
t1 = t2 - t3Difference of t2 and t3 . Afterwards t1 == t2 - t3 and t2 == t1 + t3 are true. (1)(6)
t1 = t2 i or t1 = i t2Delta 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 t2Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
f = t2 / t3Division (3) of overall duration t2 by interval unit t3 . Returns a float object.
t1 = t2 / f or t1 = t2 / iDelta 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 // t3The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
t1 = t2 % t3The 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.
+t1Returns a timedelta object with the same value. (2)
-t1equivalent 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 , H:MM:SS , where D is negative for negative t . (5)
repr(t)Returns a string representation of the timedelta object as a constructor call with canonical attribute values.

Table

DirectiveMeaningExampleNotes
%aWeekday as localeas abbreviated name.Sun, Mon, a, Sat (en_US); So, Mo, a, Sa (de_DE)(1)
%AWeekday as localeas full name.Sunday, Monday, a, Saturday (en_US); Sonntag, Montag, a, Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, a, 6
%dDay of the month as a zero-padded decimal number.01, 02, a, 31
%bMonth as localeas abbreviated name.Jan, Feb, a, Dec (en_US); Jan, Feb, a, Dez (de_DE)(1)
%BMonth as localeas full name.January, February, a, December (en_US); Januar, Februar, a, Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, a, 12
%yYear without century as a zero-padded decimal number.00, 01, a, 99
%YYear with century as a decimal number.1970, 1988, 2001, 2013
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, a, 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, a, 12
%pLocaleas equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (2)
%MMinute as a zero-padded decimal number.00, 01, a, 59
%SSecond as a zero-padded decimal number.00, 01, a, 59(3)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, a, 999999(4)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(5)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, a, 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, a, 53(6)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, a, 53(6)
%cLocaleas appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocaleas appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocaleas appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

tzinfo Objects A

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

The Date object represents the date in the idealized calendar, current Gregorian calendar indefinitely extends in both directions. January 1st of year 1 is call day number 1, January 2nd of year 1 is call day number 2, and so on. This matches the definition of the proleptic Gregorian calendar in Dershowitz and Reingolds book Calendrical Calculations, where its base calendar for all computations. See book For algorithms for converting between proleptic Gregorian ordinals and many other calendar systems. Class datetime. Date All arguments are require. Arguments may be integers, in following ranges: MINYEAR < = year < = MAXYEAR 1 < = month < = 12 1 < = day < = number of days in give month and year If argument outside those ranges is give, ValueError is Raise. Classmethod date. Today Return current local date. This is equivalent to date. Fromtimestamptime. Time. Classmethod date. Fromtimestamp Return local date corresponding to POSIX timestamp, such as is Return by time. Time. This may raise OverflowError, if timestamp is out of range of values supported by platform C localtime function, and OSError on localtime failure. It is 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 timestamp, leap seconds are ignored by fromtimestamp. Change to version 3. 3: Raise OverflowError instead of ValueError If timestamp is out of range of values supported by platform C localtime function. Raise OSError instead of ValueError on localtime failure. Classmethod date. Fromordinal return date corresponds to proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. Valueerror is Raise unless 1 < = ordinal < = date. Max. Toordinal. For any date date. Fromordinald. Toordinal = d. Date. Earliest representable date, date. Date. Max latest representable date, date. Date. Resolution smallest possible difference between non - equal date objects, timedelta. Date. Year between MINYEAR and MAXYEAR inclusive. Date. Months Between 1 and 12 inclusive. Date. Day Between 1 and number of days in give month of give year. Date2 is moved forward in time If timedelta. Days > 0, or backward if timedelta. Days < 0. Afterward date2 - date1 = timedelta. Days. Timedelta. Second and timedelta. Microseconds are ignore. Overflowerror is Raise If date2. The year would be smaller than MINYEAR or larger than MAXYEAR. This isnt quite equivalent to date1 +, because - timedelta in isolation can overflow in cases where date1 - timedelta do not. Timedelta. Second and timedelta. Microseconds are ignore. This is exact, and cannot overflow. Timedelta. Second and timedelta. Microseconds are 0, and date2 + timedelta = date1 after. 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 Raise TypeError if other comparand isnt also date object. However, NotImplemented is Return instead if other comparison has timetuple attribute.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Supported operations:

OperationResult
t1 = t2 + t3Sum of t2 and t3 . Afterwards t1 - t2 == t3 and t1 - t3 == t2 are true. (1)
t1 = t2 - t3Difference of t2 and t3 . Afterwards t1 == t2 - t3 and t2 == t1 + t3 are true. (1)
t1 = t2 i or t1 = i t2Delta 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 t2Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
f = t2 / t3Division (3) of t2 by t3 . Returns a float object.
t1 = t2 / f or t1 = t2 / iDelta 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 // t3The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
t1 = t2 % t3The 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.
+t1Returns a timedelta object with the same value. (2)
-t1equivalent 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 , H:MM:SS , where D is negative for negative t . (5)
repr(t)Returns a string in the form datetime.timedelta(D) , where D is negative for negative t . (5)

Table

DirectiveMeaningExampleNotes
%aWeekday as locales abbreviated name.Sun, Mon, ..., Sat (en_US); So, Mo, ..., Sa (de_DE)(1)
%AWeekday as locales full name.Sunday, Monday, ..., Saturday (en_US); Sonntag, Montag, ..., Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, ..., 6
%dDay of the month as a zero-padded decimal number.01, 02, ..., 31
%bMonth as locales abbreviated name.Jan, Feb, ..., Dec (en_US); Jan, Feb, ..., Dez (de_DE)(1)
%BMonth as locales full name.January, February, ..., December (en_US); Januar, Februar, ..., Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, ..., 12
%yYear without century as a zero-padded decimal number.00, 01, ..., 99
%YYear with century as a decimal number.0001, 0002, ..., 2013, 2014, ..., 9998, 9999(2)
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, ..., 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, ..., 12
%pLocales equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (3)
%MMinute as a zero-padded decimal number.00, 01, ..., 59
%SSecond as a zero-padded decimal number.00, 01, ..., 59(4)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, ..., 999999(5)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(6)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, ..., 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, ..., 53(7)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, ..., 53(7)
%cLocales appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocales appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocales appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

strftime() and strptime() Behavior A

Date

StringOutput
20122012-01-01T00:00:00+00:00
2012-05-032012-05-03T00:00:00+00:00
201205032012-05-03T00:00:00+00:00
2012-052012-05-01T00:00:00+00:00

Date and Time functions, inner function - strptime - converts your string to epoch, and outer - strftime - converts / extracts parts you want, and in what order from epoch. In Splunk Web, _time field appears in human readable format on the UI but is stored in UNIX Time. If you attempt to use strptime Function on _time field, no action is performed on values in field. Usage of Splunk Commands: CONVERT, This topic lists variables that you can use to define time formats in evaluation functions, strftime and strptime. You can also use theseA Effective Usage of aSTRPTIMEa and aSTRFTIMEa Below is the Effective Usage of aSTRPTIMEa and aSTRFTIMEa Function which are used with Eval command in SPLUNKContinue reading Splunk Eval Commands With Examples, This Function takes UNIX Time value, X, as first argument and renders Time as string using format specify by Y. Unix Time must be in seconds. Use the first 10 digits of UNIX Time to use Time in seconds. Date and Time format variables. This topic lists variables that you can use to define time formats in evaluation functions, strftime and strptime. You can also use these variables to describe timestamps in event data. Additionally, you can use relative_time and now Time functions as arguments.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Datetime

StringOutput
20161001T143028+05302016-10-01T14:30:28+05:30
20161001T142016-10-01T14:00:00+00:00

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Intervals

StringOutput
2007-03-01T13:00:00Z/2008-05-11T15:30:00Z2007-03-01T13:00:00+00:00 -> 2008-05-11T15:30:00+00:00
2008-05-11T15:30:00Z/P1Y2M10DT2H30M2008-05-11T15:30:00+00:00 -> 2009-07-21T18:00:00+00:00
P1Y2M10DT2H30M/2008-05-11T15:30:00Z2007-03-01T13:00:00+00:00 -> 2008-05-11T15:30:00+00:00

Ordinal day

StringOutput
2012-0072012-01-07T00:00:00+00:00
20120072012-01-07T00:00:00+00:00

RFC 3339

StringOutput
1996-12-19T16:39:57-08:001996-12-19T16:39:57-08:00
1990-12-31T23:59:59Z1990-12-31T23:59:59+00:00

Supported operations:

OperationResult
datetime2 = datetime1 + timedelta(1)
datetime2 = datetime1 - timedelta(2)
timedelta = datetime1 - datetime2(3)
datetime1 < datetime2Compares datetime to datetime . (4)

Table

DirectiveMeaningExampleNotes
%aWeekday as localeas abbreviated name.Sun, Mon, a, Sat (en_US); So, Mo, a, Sa (de_DE)(1)
%AWeekday as localeas full name.Sunday, Monday, a, Saturday (en_US); Sonntag, Montag, a, Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, a, 6
%dDay of the month as a zero-padded decimal number.01, 02, a, 31
%bMonth as localeas abbreviated name.Jan, Feb, a, Dec (en_US); Jan, Feb, a, Dez (de_DE)(1)
%BMonth as localeas full name.January, February, a, December (en_US); Januar, Februar, a, Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, a, 12
%yYear without century as a zero-padded decimal number.00, 01, a, 99
%YYear with century as a decimal number.1970, 1988, 2001, 2013
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, a, 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, a, 12
%pLocaleas equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (2)
%MMinute as a zero-padded decimal number.00, 01, a, 59
%SSecond as a zero-padded decimal number.00, 01, a, 59(3)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, a, 999999(4)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(5)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, a, 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, a, 53(6)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, a, 53(6)
%cLocaleas appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocaleas appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocaleas appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%

Table2

StringOutput
00:002016-12-17T00:00:00+00:00
12:04:232016-12-17T12:04:23+00:00
1204232016-12-17T12:04:23+00:00
12:04:23.452016-12-17T12:04:23.450000+00:00

Table3

TimeLT8:30 PM
Time with secondsLTS8:30:25 PM
Month numeral, day of month, yearL09/04/1986
Month name, day of month, yearLLSeptember 4 1986
Month name, day of month, year, timeLLLSeptember 4 1986 8:30 PM
Month name, day of month, day of week, year, timeLLLLThursday, September 4 1986 8:30 PM

Table4

DirectiveMeaningExampleNotes
%aWeekday as localeas abbreviated name.Sun, Mon, a, Sat (en_US); So, Mo, a, Sa (de_DE)(1)
%AWeekday as localeas full name.Sunday, Monday, a, Saturday (en_US); Sonntag, Montag, a, Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, a, 6
%dDay of the month as a zero-padded decimal number.01, 02, a, 31(9)
%bMonth as localeas abbreviated name.Jan, Feb, a, Dec (en_US); Jan, Feb, a, Dez (de_DE)(1)
%BMonth as localeas full name.January, February, a, December (en_US); Januar, Februar, a, Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, a, 12(9)
%yYear without century as a zero-padded decimal number.00, 01, a, 99(9)
%YYear with century as a decimal number.0001, 0002, a, 2013, 2014, a, 9998, 9999(2)
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, a, 23(9)
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, a, 12(9)
%pLocaleas equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (3)
%MMinute as a zero-padded decimal number.00, 01, a, 59(9)
%SSecond as a zero-padded decimal number.00, 01, a, 59(4), (9)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, a, 999999(5)
%zUTC offset in the form AHHMM (empty string if the object is naive).(empty), +0000, -0400, +1030, +063415, -030712.345216(6)
%ZTime zone name (empty string if the object is naive).(empty), UTC, GMT(6)
%jDay of the year as a zero-padded decimal number.001, 002, a, 366(9)
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, a, 53(7), (9)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, a, 53(7), (9)
%cLocaleas appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocaleas appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocaleas appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%

Table5

DirectiveMeaningExampleNotes
%GISO 8601 year with century representing the year that contains the greater part of the ISO week ( %V ).0001, 0002, a, 2013, 2014, a, 9998, 9999(8)
%uISO 8601 weekday as a decimal number where 1 is Monday.1, 2, a, 7
%VISO 8601 week as a decimal number with Monday as the first day of the week. Week 01 is the week containing Jan 4.01, 02, a, 53(8), (9)

Week number

StringOutput
2012-W052012-01-30T00:00:00+00:00
2012W052012-01-30T00:00:00+00:00
2012-W05-52012-02-03T00:00:00+00:00
2012W0552012-02-03T00:00:00+00:00
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Technical Detail A

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Date, datetime, and time objects all support the strftime method, to create a string representing time under control of explicit format string. Broadly speaking, dstrftime acts like time module time. Strftimefmt, dtimetuple although not all objects support the timetuple method. Conversely, datetime. The Strptime class method creates a datetime object from string representing date and time and corresponding format string. Datetime. Strptime is equivalent to datetime * time. Strptime. For time objects, format codes for year,s month,s and days should not be used as time objects have no such values. If theyre used anyway, 1900 is substitute for year, and 1 for month and day. For date objects, format codes for hours, minutes, seconds, and microseconds should not be used as date objects have no such values. If theyre used anyway, 0 is substitute for them. The full set of format codes support varies across platforms, because Python calls platform C librarys strftime function, and platform variations are common. To see the full set of format codes supported on your platform, consult strftime documentation. The following is a list of all format codes that C standards require, and these work on all platforms with standard C implementation. Note that the 1999 version of C standard added additional format codes. Because format depends on current locale, care should be taken when making assumptions about output value. Field orderings will vary, and output may contain Unicode characters encoded using locales default encoding. The Strptime method can parse years in full range, but years < 1000 must be zero - fill to 4 - digit width. Change to version 3. 2: in previous versions, strftime method was restricted to years > = 1900. Change to version 3. 3: in version 3. 2, strftime method was restricted to years > = 1000. When used with the strptime method,% p directive only affects output hour field if the% I directive is used to parse hour.S Unlike the time module, datetime module does not support leap seconds. When used with the strptime method,% f directive accepts from one to six digits and zero pads on right.% F is extension to set of format characters in C standard. For naive object,% Z and% Z format codes are replaced by empty strings. For awareness object:% Z utcoffset is transformed into a 5 - character string of form + HHMM or - HHMM, where HH is a 2 - digit string giving the number of UTC offset hours, and MM is a 2 - digit string giving the number of UTC offset minutes. For example, if utcoffset returns timedelta,% Z is replaced with string - 0330.% Z If tzname returns None,% Z is replaced by empty string. Otherwise,% Z is replaced by returned value, which must be string. Change to version 3. 2: When% Z directive is provided to strptime method, aware datetime object will be produce.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Supported operations:

OperationResult
t1 = t2 + t3Sum of t2 and t3 . Afterwards t1 - t2 == t3 and t1 - t3 == t2 are true. (1)
t1 = t2 - t3Difference of t2 and t3 . Afterwards t1 == t2 - t3 and t2 == t1 + t3 are true. (1)
t1 = t2 i or t1 = i t2Delta 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 t2Delta multiplied by a float. The result is rounded to the nearest multiple of timedelta.resolution using round-half-to-even.
f = t2 / t3Division (3) of t2 by t3 . Returns a float object.
t1 = t2 / f or t1 = t2 / iDelta 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 // t3The floor is computed and the remainder (if any) is thrown away. In the second case, an integer is returned. (3)
t1 = t2 % t3The 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.
+t1Returns a timedelta object with the same value. (2)
-t1equivalent 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 , H:MM:SS , where D is negative for negative t . (5)
repr(t)Returns a string in the form datetime.timedelta(D) , where D is negative for negative t . (5)

Table

DirectiveMeaningExampleNotes
%aWeekday as locales abbreviated name.Sun, Mon, ..., Sat (en_US); So, Mo, ..., Sa (de_DE)(1)
%AWeekday as locales full name.Sunday, Monday, ..., Saturday (en_US); Sonntag, Montag, ..., Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, ..., 6
%dDay of the month as a zero-padded decimal number.01, 02, ..., 31
%bMonth as locales abbreviated name.Jan, Feb, ..., Dec (en_US); Jan, Feb, ..., Dez (de_DE)(1)
%BMonth as locales full name.January, February, ..., December (en_US); Januar, Februar, ..., Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, ..., 12
%yYear without century as a zero-padded decimal number.00, 01, ..., 99
%YYear with century as a decimal number.0001, 0002, ..., 2013, 2014, ..., 9998, 9999(2)
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, ..., 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, ..., 12
%pLocales equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (3)
%MMinute as a zero-padded decimal number.00, 01, ..., 59
%SSecond as a zero-padded decimal number.00, 01, ..., 59(4)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, ..., 999999(5)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(6)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, ..., 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, ..., 53(7)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, ..., 53(7)
%cLocales appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocales appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocales appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Introduction

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Working with dates and times is one of the biggest challenges in programming. Between dealing with Time Zones, daylight saving time, and different write date formats, it can be tough to keep track of which days and times youre referencing. Fortunately, built - in Python datetime module can help you manage the complex nature of dates and times. Why is programming with dates and times such a challenge? Which functions are available in Python datetime module How to print or read dates and time in specific format How to do arithmetic with dates and times plus, you are going to develop a neat application to count down time remaining until the next PyCon US!


Creating Python datetime Instances #

Python datetime instances support two types of operation, naive and aware. The basic difference between them is that naive instances do contain time zone information, whereas aware instances do. More formally, to quote Python documentation: this is an important distinction for working with Python datetime. Aware datetime instance can compare itself unambiguously to other aware datetime instances and will always return the correct time interval when used in arithmetic operations. Naive datetime instances, on other hand, may be ambiguous. One example of this ambiguity relates to daylight saving time. Areas that practice daylight saving time turn clocks forward one hour in spring and backward one hour in fall. This typically happens at 2: 00 AM local time. In spring, hours from 2: 00 AM to 2: 59 AM never happen, and in fall, hours from 1: 00 AM to 1: 59 AM happen twice! Practically, what happens is that offset from UTC in these time zones changes throughout the year. Iana tracks these changes and catalogs them in different database files that your computer has installed. Using a library like dateutil, which uses IANA database under hood, is a great way to make sure that your code properly handles arithmetic with time. This doesnt mean that you always need to be aware of datetime instances. But aware instances are crucial if youre comparing times with each other, especially if youre comparing times in different parts of the world.


Example 1: Get Current Date and Time

Nearly all computers count time from an instant called Unix epoch. This occurred on January 1 1970, at 00: 00: 00 UTC. Utc stands for coordinate Universal Time and refers to Time at longitude of 0. Utc is often also called Greenwich Mean Time, or GMT. UTC is not adjusted for daylight saving time, so it consistently lasts twenty - four hours every day. By definition, Unix Time elapses at the same rate as UTC, so one - second step in UTC corresponds to one - second step in Unix Time. You can usually figure out the date and time in UTC of any given instant since January 1 1970, by counting the number of seconds since Unix epoch, with the exception of leap seconds. Leap seconds are occasionally added to UTC to account for the slowing of Earth's rotation but are not added to Unix Time. Nearly all programming languages, including Python, incorporate the concept of Unix Time. The Python standard library includes a module called Time that can print the number of seconds since Unix epoch: in this example, you import Time module and execute Time to print Unix Time, or number of seconds since epoch. In addition to Unix Time, computers need a way to convey time information to users. As you saw in the last example, Unix Time is nearly impossible for humans to parse. Instead, Unix Time is typically converted to UTC, which can then be converted into local Time using Time zone offsets. The Internet assign Numbers Authority maintains a database of all of values of Time zone offsets. Iana also releases regular updates that include any changes in time zone offsets. This database is often included with your operating system, although certain applications may include updated copy. The database contains copies of all designated time zones and how many hours and minutes theyre offset from UTC. So, during winter, when daylight saving Time is not in effect, US Eastern Time zone has an offset of - 05: 00, or negative five hours from UTC. Other regions have different offsets, which may not be integer hours. Utc offset for Nepal, for example, is + 05: 45, or positive five hours and forty - five minutes from UTC.


Python format datetime

A datetime object is a single object containing all information from date object and time object. Like date object, datetime assumes the current Gregorian calendar extends in both directions; like time object, datetime assumes there are exactly 3600 * 24 seconds every day. Class datetime. Datetime year, month and day arguments are require. Tzinfo may be none, or instance of tzinfo subclass. Remaining arguments may be integers, in following ranges: MINYEAR < = year < = MAXYEAR 1 < = month < = 12 1 < = day < = number of days in give month and year 0 < = hour < 24 0 < = minute < 60 0 < = second < 60 0 < = microsecond < 1000000 If argument outside those ranges is give, ValueError is Raise. Classmethod datetime. Today return to current local datetime, with tzinfo None. This is equivalent to datetime. Fromtimestamptime. Time. See also now, fromtimestamp. Classmethod datetime. Now return to the current local date and time. If optional argument TZ is none or not specify, this is like today, but, if possible, supplies more precision than can be get from going through time. Time timestamp. Else TZ must be instance of class TZINFO subclass, and current date and time are Convert to TZ s Time zone. In this case, result is equivalent to TZ. Fromutcdatetime. Utcnow. Replace. See also today, utcnow. Classmethod datetime. You return the current UTC date and time, with tzinfo None. This is like now, but returns current UTC date and time, as naive datetime object. Aware current UTC datetime can be obtained by calling datetime. Now. See also now. Classmethod datetime. Fromtimestamp Return local date and time corresponding to POSIX timestamp, such as is Return by Time. Time. If optional argument TZ is none or is not specify, timestamp is Convert to platforms local date and time, and the return datetime object is naive. Else TZ must be instance of class TZINFO subclass, and the timestamp is Convert to TZ s Time zone. In this case, result is equivalent to TZ. Fromutcdatetime. Utcfromtimestamp. Replace. Fromtimestamp may raise OverflowError, if timestamp is out of range of values supported by platform C localtime or gmtime functions, and OSError on localtime or gmtime failure. It is 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 timestamp, leap seconds are ignored by fromtimestamp, and then it is possible to have two timestamps differing by second that yield identical datetime objects. See also utcfromtimestamp. Change to version 3. 3: Raise OverflowError instead of ValueError If timestamp is out of range of values supported by platform C localtime or gmtime functions. Raise OSError instead of ValueError on localtime or gmtime failure. Classmethod datetime. Utcfromtimestamp Return UTC datetime corresponding to POSIX timestamp, with tzinfo None.


Starting Your PyCon Countdown #

Now that you know how to add time zone information to Python datetime instance, you can improve your PyCon countdown code. Earlier, you used standard datetime constructor to pass the year, month, day, and hour that PyCon will start. You can update your code to use dateutil. Parser module, which provides a more natural interface for creating datetime instances: in this code, you import parser and TZ from dateutil and datetime from datetime. Next, you use a parser. Please to read the date of next PyCon US from string. This is much more readable than plain datetime constructor. Parser. Parse returns naive datetime instance, so you use. It Replace to change TZINFO to America / New New New New New_York time zone. Pycon US 2021 will take place in Pittsburgh, Pennsylvania, which is in the US Eastern time zone. The canonical name for that time zone is America / York since New York City is the largest city in the time zone. Pycon_date is aware of datetime instance with time zone set to US Eastern time. Since May 12 is after Daylight saving time takes effect, time zone name is EDT, or Eastern Daylight Time. Next, you create now to represent the current instant of time and give it your local time zone. Last, you find the timedelta between PYCON_DATE and now and print result. If youre in a locale that does not adjust clocks for Daylight saving time, then you may see the number of hours remaining until PyCon change by hour.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Supported operations:

OperationResult
datetime2 = datetime1 + timedelta(1)
datetime2 = datetime1 - timedelta(2)
timedelta = datetime1 - datetime2(3)
datetime1 < datetime2Compares datetime to datetime . (4)

Table

DirectiveMeaningExampleNotes
%aWeekday as locales abbreviated name.Sun, Mon, ..., Sat (en_US); So, Mo, ..., Sa (de_DE)(1)
%AWeekday as locales full name.Sunday, Monday, ..., Saturday (en_US); Sonntag, Montag, ..., Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, ..., 6
%dDay of the month as a zero-padded decimal number.01, 02, ..., 31
%bMonth as locales abbreviated name.Jan, Feb, ..., Dec (en_US); Jan, Feb, ..., Dez (de_DE)(1)
%BMonth as locales full name.January, February, ..., December (en_US); Januar, Februar, ..., Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, ..., 12
%yYear without century as a zero-padded decimal number.00, 01, ..., 99
%YYear with century as a decimal number.0001, 0002, ..., 2013, 2014, ..., 9998, 9999(2)
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, ..., 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, ..., 12
%pLocales equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (3)
%MMinute as a zero-padded decimal number.00, 01, ..., 59
%SSecond as a zero-padded decimal number.00, 01, ..., 59(4)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, ..., 999999(5)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(6)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, ..., 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, ..., 53(7)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, ..., 53(7)
%cLocales appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocales appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocales appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Conclusion

Unix Time is how computers count time, but it would be incredibly inefficient for humans to determine time by calculating the number of seconds from arbitrary date. Instead, we work in terms of years, months, days, and so forth. But even with these conventions in place, another layer of complexity stems from the fact that different languages and cultures have different ways of writing date. For instance, in the United States, dates are usually written starting with month, then day, then year. This means that January 31, 2020, is written as 01 - 31 - 2020. This closely matches the long - form written version of the date. However, most of Europe and many other areas write dates starting with day, then month, then year. This means that January 31 2020, is written as 31 - 01 - 2020. These differences can cause all sorts of confusion when communicating across cultures. To help avoid communication mistakes, International Organization for Standardization developed ISO 8601. This Standard specifies that all dates should be written in order of most - to - least - significant data. This mean format is year, month, day, hour, minute, and second: in this example, YYYY represents four - digit year, and MM and DD are two - digit month and day, starting with zero if necessary. After that, HH, MM, and SS represent two - digit hours, minutes, and seconds, starting with zero if necessary. The advantage of this format is that date can be represented with no ambiguity. Dates written as DD - MM - YYYY or MM - DD - YYYY can be misinterpreted if day is a valid month number. Youll see little later on how you can use the ISO 8601 format with Python datetime.


Creating Python datetime Instances #

Another way to create date instances is to use. Them Fromisoformat. To use this method, you provide string with date in ISO 8601 format that you learned about earlier. For instance, you might provide a string with year, month, and date specify: This string represents the date January 31 2020, according to ISO 8601 format. You can create a date instance with the following example: in this code, you use date. Fromisoformat to create a date, for instance for January 31 2020. This method is very useful because it based on the ISO 8601 standard. But what if you have string that represents date and time but isnt in ISO 8601 format? Fortunately, Python datetime provides method call. Strptime to handle this situation. This method uses special mini - language to tell Python which parts of string are associated with datetime attribute. To construct datetime from string Strptime, you have to tell Python what each of the parts of string represents using formatting codes from mini - language. You can try this example to see how. Strptime works: on line 1, you create a date_string, which represents the date and time January 31 2020, at 2: 45: 37 PM. On line 2, you create format_string, which uses mini - language to specify how parts of date_string will be turned into datetime attributes. In format_string, you include several formatting codes and all of the dashes, colons, and spaces exactly as they appear in date_string. To process date and time in date_string, you include the following formatting codes: complete listing of all of the options in mini - language is outside the scope of this tutorial, but you can find several good references on the web, including in Python documentation and on a website called strftime. Org. Now that date_string and format_string are define, you can use them to create datetime instance. Here is an example of how. Strptime works: in this code, you import datetime on line 3 and use datetime. Strptime with date_string and format_string on line 4. Finally, line 5 shows values of attributes in datetime instance created by. Strptime. You can see that they match values shown in the table above.


Starting Your PyCon Countdown #

Now you have enough information to start working on the countdown clock for next year's PyCon US! Pycon US 2021 will start on May 12 2021 in Pittsburgh, PA. With the 2020 event having been cancel, many Pythonistas are extra excited about next year's gathering. This is a great way to keep track of how long youll need to wait and boost your datetime skills at the same time! To get start, create a file called pyconcd. Py and add this code: in this code, you import datetime from datetime and define a constant, PYCON_DATE, that stores the date of the next PyCon US. You dont expect the date of PyCon to change, so you name variable in all caps to indicate that its constant. Next, you compute the difference between datetime. Now, which is current time, and PYCON_DATE. Taking the difference between two datetime instances returns datetime. Timedelta instance. Timedelta instances represent change in time between two datetime instances. Delta in name is a reference to the Greek letter delta, which is used in science and engineering to mean change. Youll learn more later about how to use timedelta for more general arithmetic operations. Finally, print output, as of April 9 2020 at little before 9: 30 PM is: only 397 days until PyCon US 2021! This output is a little clunky, so later on youll see how you can improve formatting. If you run this script on different day, youll get different output. If you run script after May 12 2021 at 8: 00 AM, youll get a negative amount of time remaining!

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Python datetime Classes

Different functions available in date class are -

Function nameDescription
fromtimestamp(timestamp)Return the local date corresponding to the POSIX timestamp
fromordinal(ordinal)Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.
fromisoformat(date_string)Return a date corresponding to a date_string given in the format YYYY-MM-DD:
fromisocalendar(year, week, day)Return a date corresponding to the ISO calendar date specified by year, week and day.

In Python, date, Time and datetime classes provide a number of functions to deal with dates, times and time intervals. Date and datetime are objects in Python, so when you manipulate them, you are actually manipulating objects and not strings or timestamps. Whenever you manipulate dates or time, you need to import datetime function. Datetime classes in Python are categorized into main 5 classes. Date - Manipulate just date Time - Time independent of day. Datetime - Combination of Time and date timedelta duration of Time used for manipulating dates. Tzinfo abstract class For dealing with Time Zones


Starting Your PyCon Countdown #

The final step that you want to take is to follow Python best practices and put code that produces output into the main function. You can check out the full, final code after applying all these changes: in this code, you move print and code used for generator into the main. On line 23, you use guard clause to make sure that the main only runs when this file is executed as script. This allows other people to import your code and reuse PYCON_DATE, for instance, if theyd like. Now you can modify this script as much as you want. One neat thing to do might be to allow users to change time zone associated with now by passing command - line argument. You could also change PYCON_DATE to something closer to home, say PyCon Africa or EuroPython. To get even more excited about PyCon, check out Real Python at PyCon US 2019 and How to Get Most Out of PyCon!

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Other fucntions of datetime class are -

Fucntion nameDescription
utcnow()Return the current UTC date and time, with tzinfo None.
fromtimestamp(timestamp, tz=None)Return the local date and time corresponding to the POSIX timestamp.
utcfromtimestamp(timestamp)Return the UTC datetime corresponding to the POSIX timestamp, with tzinfo None.
fromordinal(ordinal)Return the datetime corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1.
combine(date, time, tzinfo=self.tzinfo)Return a new datetime object whose date components are equal to the given date objects, and whose time components are equal to the given time objects.
fromisoformat(date_string)Return a datetime corresponding to a date_string in one of the formats emitted by date.isoformat() and datetime.isoformat().
strptime(date_string, format)Return a datetime corresponding to date_string, parsed according to format.

Supported operations:

OperationResult
datetime2 = datetime1 + timedelta(1)
datetime2 = datetime1 - timedelta(2)
timedelta = datetime1 - datetime2(3)
datetime1 < datetime2Compares datetime to datetime . (4)

Table

DirectiveMeaningExampleNotes
%aWeekday as localeas abbreviated name.Sun, Mon, a, Sat (en_US); So, Mo, a, Sa (de_DE)(1)
%AWeekday as localeas full name.Sunday, Monday, a, Saturday (en_US); Sonntag, Montag, a, Samstag (de_DE)(1)
%wWeekday as a decimal number, where 0 is Sunday and 6 is Saturday.0, 1, a, 6
%dDay of the month as a zero-padded decimal number.01, 02, a, 31
%bMonth as localeas abbreviated name.Jan, Feb, a, Dec (en_US); Jan, Feb, a, Dez (de_DE)(1)
%BMonth as localeas full name.January, February, a, December (en_US); Januar, Februar, a, Dezember (de_DE)(1)
%mMonth as a zero-padded decimal number.01, 02, a, 12
%yYear without century as a zero-padded decimal number.00, 01, a, 99
%YYear with century as a decimal number.1970, 1988, 2001, 2013
%HHour (24-hour clock) as a zero-padded decimal number.00, 01, a, 23
%IHour (12-hour clock) as a zero-padded decimal number.01, 02, a, 12
%pLocaleas equivalent of either AM or PM.AM, PM (en_US); am, pm (de_DE)(1), (2)
%MMinute as a zero-padded decimal number.00, 01, a, 59
%SSecond as a zero-padded decimal number.00, 01, a, 59(3)
%fMicrosecond as a decimal number, zero-padded on the left.000000, 000001, a, 999999(4)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(empty), +0000, -0400, +1030(5)
%ZTime zone name (empty string if the object is naive).(empty), UTC, EST, CST
%jDay of the year as a zero-padded decimal number.001, 002, a, 366
%UWeek number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.00, 01, a, 53(6)
%WWeek number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0.00, 01, a, 53(6)
%cLocaleas appropriate date and time representation.Tue Aug 16 21:30:00 1988 (en_US); Di 16 Aug 21:30:00 1988 (de_DE)(1)
%xLocaleas appropriate date representation.08/16/88 (None); 08/16/1988 (en_US); 16.08.1988 (de_DE)(1)
%XLocaleas appropriate time representation.21:30:00 (en_US); 21:30:00 (de_DE)(1)
%%A literal '%' character.%
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Creating Date Objects

Instance attributes (read-only):

AttributeValue
daysBetween -999999999 and 999999999 inclusive
secondsBetween 0 and 86399 inclusive
microsecondsBetween 0 and 999999 inclusive

Time values are represented with Time class. Times have attributes For hour, minute, second, and microsecond. They can also include time zone information. Arguments to initialize time instance are optional, but default of 0 is unlikely to be what you want. Time, for instance, only holds values of time, and not dates associated with time. Min and max class attributes reflect valid range of times in a single day. In fact, using floating point numbers for microsecond argument generates a TypeError. Calendar date values represent date class. Instances have attributes For year, month, and day. It is easy to create a date representing today's date using today's class method. There are also class methods for creating instances from integers or POSIX timestamp values. This example illustrates different value types used by fromordinal and fromtimestamp. As with time, range of date values support can be determined using min and max attributes. Another way to create a new date is use replace method of existing date. For example, you can change year, leaving day and month alone. Using replace is not the only way to calculate future / past dates. You can use datetime to perform basic arithmetic on date values via timedelta class. Subtracting dates produce timedelta, and timedelta can be added or subtracted from date to produce another date. Internal values for timedelta are stored in days, seconds, and microseconds. Intermediate level values passed to constructor are converted into days, seconds, and microseconds.


Python Datetime

Python datetime and dateutil are a powerful combination of libraries when youre working with dates and times. Dateutil is even recommended in Python documentation. However, there are many other libraries that you can use to work with dates and times in Python. Some of these rely on datetime and dateutil, while others are completely independent replacements: Pytz provides time zone information similar to dateutil. It uses a somewhat different interface than standard datetime. Tzinfo, so be aware of potential problems if you decide to use it. Arrow provides drop - in replacement for datetime. It was inspired by a moment. Js, so if youre coming from web development, then this might be a more familiar interface. The pendulum provides another drop - in replacement for datetime. It includes time zone interface and improved timedelta implementation. Maya provides a similar interface as datetime. It relies on the Pendulum for parts of the parsing library. Dateparser provides an interface to generate datetime instances from human - readable text. It is flexible and supports many languages. In addition, if you work heavily with NumPy, Pandas, or other data science packages, then there are a few options that might be useful to you: NumPy provides a similar API to the built - in Python datetime library, but the NumPy version can be used in arrays. Pandas provide support for Time - series data in DataFrames, usually sequential values of Time - base events, by using the NumPy datetime module. Cftime provides support for calendars other than the proleptic Gregorian calendar as well as other time units conforming to Climate and Forecasting conventions. Its used by xarray package to provide Time - series support.


Starting Your PyCon Countdown #

Earlier, you learn about creating datetime instances Strptime. This method uses special mini - language within Python to specify how date string is format. Python datetime has additional method call. Strftime that allows you to format datetime instance into string. In a sense, it reverse operation of parsing Strptime. You can differentiate between two methods by remembering that p in. Strptime stands for parse, and f in. Strftime stands for format. In your PyCon countdown, you can use. Strftime to print output to let user know the date on which PyCon US will start. Remember, you can find formatting codes that you want to use on strftime. Org. Now add this code on line 18 of your PyCon countdown script: in this code, line 18 is uses. Strftime to create string representing the starting date of PyCon US 2021. Output includes weekday, month, day, year, hour, minute, AM or PM, and time zone: on line 19, you print this string for users to see with some explanatory text. The last line prints the amount of time remaining until PyCon start date. Next, youll finish your script to make it easier for other people to reuse.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

Supported operations:

OperationResult
date2 = date1 + timedeltadate2 is timedelta.days days removed from date1 . (1)
date2 = date1 - timedeltaComputes date2 such that date2 + timedelta == date1 . (2)
timedelta = date1 - date2(3)
date1 < date2date1 is considered less than date2 when date1 precedes date2 in time. (4)

Table

DirectiveMeaningNotes
%aLocales abbreviated weekday name.
%ALocales full weekday name.
%bLocales abbreviated month name.
%BLocales full month name.
%cLocales appropriate date and time representation.
%dDay of the month as a decimal number .
%fMicrosecond as a decimal number , zero-padded on the left(1)
%HHour (24-hour clock) as a decimal number .
%IHour (12-hour clock) as a decimal number .
%jDay of the year as a decimal number .
%mMonth as a decimal number .
%MMinute as a decimal number .
%pLocales equivalent of either AM or PM.(2)
%SSecond as a decimal number .(3)
%UWeek number of the year (Sunday as the first day of the week) as a decimal number . All days in a new year preceding the first Sunday are considered to be in week 0.(4)
%wWeekday as a decimal number .
%WWeek number of the year (Monday as the first day of the week) as a decimal number . All days in a new year preceding the first Monday are considered to be in week 0.(4)
%xLocales appropriate date representation.
%XLocales appropriate time representation.
%yYear without century as a decimal number .
%YYear with century as a decimal number (strptime), (strftime).(5)
%zUTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).(6)
%ZTime zone name (empty string if the object is naive).
%%A literal '%' character.
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Python Time as an Object #

Supported operations:

OperationResult
datetime2 = datetime1 + timedelta(1)
datetime2 = datetime1 - timedelta(2)
timedelta = datetime1 - datetime2(3)
datetime1 < datetime2Compares datetime to datetime . (4)

Epoch uses UTC for its definition rather than Time zone. Therefore, seconds elapse since the epoch is not variable depending on your geographical location. However, same cannot be said of struct_time. Object representation of Python Time may or may not take your time zone into account. There are two ways to convert float representing seconds to struct_time: UTC Local Time to convert Python Time float to UTC - base struct_time, Python Time module provides a function called gmtime. You use this call to discover your systems epoch. Now, you have a better foundation for understanding what is actually happening here. Gmtime converts the number of elapsed seconds since epoch to struct_time in UTC. In this case, youve passed 0 as number of seconds, meaning youre trying to find the epoch, itself, in UTC. As you saw before, struct_time cannot represent fractional seconds, so gmtime ignores fractional seconds in argument: notice that even though the number of seconds you passed was very close to 2,. 99 fractional seconds were simply ignore, as shown by tm_sec = 1. Secs parameter for gmtime is optional, meaning you can call gmtime with no arguments. Doing so will provide current Time in UTC: interestingly, there is no inverse for this function within Time. Instead, you have to look in the Python calendar module for the function name timegm:. Timegm takes tuple and returns corresponding number of seconds since epoch. Working with UTC is valuable in programming because of its standard. You do have to worry about DST, time zone, or locale information. That say, there are plenty of cases when you want to use Local Time. Next, youll see how to convert from seconds to Local Time so that you can do just that.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Sources

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

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