datetime — Basic date and time types
New in version 2.3.
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 member 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”. This
distinction refers to whether the object has any notion of time zone, daylight
saving time, or other kind of algorithmic or political time adjustment. Whether
a naive datetime object represents Coordinated Universal Time (UTC),
local time, or time in some other timezone is purely up to the program, just
like it’s up to the program whether a particular number represents metres,
miles, or mass. Naive datetime objects are easy to understand and to
work with, at the cost of ignoring some aspects of reality.
For applications requiring more, datetime and time objects
have an optional time zone information member, tzinfo, that can contain
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 no
concrete tzinfo classes are supplied by the datetime module.
Supporting timezones at whatever level of detail is required is up to the
application. The rules for time adjustment across the world are more political
than rational, and there is no standard suitable for every application.
The datetime module exports the following constants:
-
datetime.MINYEAR
- The smallest year number allowed in a date or datetime object.
MINYEAR is 1.
-
datetime.MAXYEAR
- The largest year number allowed in a date or datetime object.
MAXYEAR is 9999.
See also
- Module calendar
- General calendar related functions.
- Module time
- Time access and conversions.
Available Types
-
class datetime.date
- 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).
Objects of these types are immutable.
Objects of the date type are always naive.
An object d of type time or datetime may be naive or aware.
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.
The distinction between naive and aware doesn’t apply to timedelta
objects.
Subclass relationships:
object
timedelta
tzinfo
time
date
datetime
A timedelta object represents a duration, the difference between two
dates or times.
-
class datetime.timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])
All arguments are optional and default to 0. Arguments may be ints, longs,
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. 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,
>>> from datetime import timedelta
>>> d = timedelta(microseconds=-1)
>>> (d.days, d.seconds, d.microseconds)
(-1, 86399, 999999)
Class attributes are:
-
timedelta.min
- The most negative timedelta object, timedelta(-999999999).
-
timedelta.max
- The most positive timedelta object, timedelta(days=999999999,
hours=23, minutes=59, seconds=59, microseconds=999999).
-
timedelta.resolution
- 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 |
Supported operations:
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 or long.
Afterwards t1 // i == t2 is true,
provided i != 0. |
|
In general, t1 * i == t1 * (i-1) + t1
is true. (1) |
t1 = t2 // i |
The floor is computed and the remainder (if
any) is thrown away. (3) |
+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) |
Notes:
- This is exact, but may overflow.
- This is exact, and cannot overflow.
- Division by 0 raises ZeroDivisionError.
- -timedelta.max is not representable as a timedelta object.
In addition to the operations listed above timedelta objects support
certain additions and subtractions with date and datetime
objects (see below).
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).
Example usage:
>>> from datetime import timedelta
>>> year = timedelta(days=365)
>>> another_year = timedelta(weeks=40, days=84, hours=23,
... minutes=50, seconds=600) # adds up to 365 days
>>> year == another_year
True
>>> ten_years = 10 * year
>>> ten_years, ten_years.days // 365
(datetime.timedelta(3650), 10)
>>> nine_years = ten_years - year
>>> nine_years, nine_years.days // 365
(datetime.timedelta(3285), 9)
>>> three_years = nine_years // 3;
>>> three_years, three_years.days // 365
(datetime.timedelta(1095), 3)
>>> abs(three_years - ten_years) == 2 * three_years + year
True
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.
-
class datetime.date(year, month, day)
All arguments are required. Arguments may be ints or longs, 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:
-
date.today()
- Return the current local date. This is equivalent to
date.fromtimestamp(time.time()).
-
date.fromtimestamp(timestamp)
- Return the local date corresponding to the POSIX timestamp, such as is returned
by time.time(). This may raise ValueError, if the timestamp is out
of the range of values supported by the platform C localtime function.
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().
-
date.fromordinal(ordinal)
- 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.
Class attributes:
-
date.min
- The earliest representable date, date(MINYEAR, 1, 1).
-
date.max
- The latest representable date, date(MAXYEAR, 12, 31).
-
date.resolution
- The smallest possible difference between non-equal date objects,
timedelta(days=1).
Instance attributes (read-only):
-
date.year
- Between MINYEAR and MAXYEAR inclusive.
-
date.month
- Between 1 and 12 inclusive.
-
date.day
- Between 1 and the number of days in the given month of the given year.
Supported operations:
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) |
Notes:
- 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.
- 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.
- 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(). 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.
Instance methods:
-
date.replace(year, month, day)
- Return a date with the same value, except for those members 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).
-
date.timetuple()
- 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(), d.toordinal() - date(d.year, 1, 1).toordinal() + 1, -1))
-
date.toordinal()
- 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.
-
date.weekday()
- 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().
-
date.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().
-
date.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
http://www.phys.uu.nl/ vgent/calendar/isocalendar.htm for a good explanation.
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).
-
date.isoformat()
- Return a string representing the date in ISO 8601 format, ‘YYYY-MM-DD’. For
example, date(2002, 12, 4).isoformat() == '2002-12-04'.
-
date.__str__()
- For a date d, str(d) is equivalent to d.isoformat().
-
date.ctime()
- 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. See
section strftime() Behavior.
Example of counting days to an event:
>>> import time
>>> from datetime import date
>>> today = date.today()
>>> today
datetime.date(2007, 12, 5)
>>> today == date.fromtimestamp(time.time())
True
>>> my_birthday = date(today.year, 6, 24)
>>> if my_birthday < today:
... my_birthday = my_birthday.replace(year=today.year + 1)
>>> my_birthday
datetime.date(2008, 6, 24)
>>> time_to_birthday = abs(my_birthday - today)
>>> time_to_birthday.days
202
Example of working with date:
>>> from datetime import date
>>> d = date.fromordinal(730920) # 730920th day after 1. 1. 0001
>>> d
datetime.date(2002, 3, 11)
>>> t = d.timetuple()
>>> for i in t:
... print i
2002 # year
3 # month
11 # day
0
0
0
0 # weekday (0 = Monday)
70 # 70th day in the year
-1
>>> ic = d.isocalendar()
>>> for i in ic:
... print i
2002 # ISO year
11 # ISO week number
1 # ISO day number ( 1 = Monday )
>>> d.isoformat()
'2002-03-11'
>>> d.strftime("%d/%m/%y")
'11/03/02'
>>> d.strftime("%A %d. %B %Y")
'Monday 11. March 2002'
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.
Constructor:
-
class datetime.datetime(year, month, day[, hour[, minute[, second[, microsecond[, tzinfo]]]]])
The year, month and day arguments are required. tzinfo may be None, or an
instance of a tzinfo subclass. The remaining arguments may be ints or
longs, 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
If an argument outside those ranges is given, ValueError is raised.
Other constructors, all class methods:
-
datetime.today()
- Return the current local datetime, with tzinfo None. This is
equivalent to datetime.fromtimestamp(time.time()). See also now(),
fromtimestamp().
-
datetime.now([tz])
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).
Else tz must be an instance of a class 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().
-
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. See also now().
-
datetime.fromtimestamp(timestamp[, tz])
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.
Else tz must be an instance of a class 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 ValueError, if the timestamp is out of
the range of values supported by the platform C localtime or
gmtime functions. 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().
-
datetime.utcfromtimestamp(timestamp)
- Return the UTC datetime corresponding to the POSIX timestamp, with
tzinfo None. This may raise ValueError, if the timestamp is
out of the range of values supported by the platform C gmtime function.
It’s common for this to be restricted to years in 1970 through 2038. See also
fromtimestamp().
-
datetime.fromordinal(ordinal)
- 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.
-
datetime.combine(date, time)
- Return a new datetime object whose date members are equal to the given
date object’s, and whose time and tzinfo members are equal to
the given time object’s. For any datetime object d, d ==
datetime.combine(d.date(), d.timetz()). If date is a datetime
object, its time and tzinfo members are ignored.
-
datetime.strptime(date_string, format)
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.
New in version 2.5.
Class attributes:
-
datetime.min
- The earliest representable datetime, datetime(MINYEAR, 1, 1,
tzinfo=None).
-
datetime.max
- The latest representable datetime, datetime(MAXYEAR, 12, 31, 23, 59,
59, 999999, tzinfo=None).
-
datetime.resolution
- The smallest possible difference between non-equal datetime objects,
timedelta(microseconds=1).
Instance attributes (read-only):
-
datetime.year
- Between MINYEAR and MAXYEAR inclusive.
-
datetime.month
- Between 1 and 12 inclusive.
-
datetime.day
- Between 1 and the number of days in the given month of the given year.
-
datetime.hour
- In range(24).
-
datetime.minute
- In range(60).
-
datetime.second
- In range(60).
-
datetime.microsecond
- In range(1000000).
-
datetime.tzinfo
- The object passed as the tzinfo argument to the datetime constructor,
or None if none was passed.
Supported operations:
Operation |
Result |
datetime2 = datetime1 + timedelta |
(1) |
datetime2 = datetime1 - timedelta |
(2) |
timedelta = datetime1 - datetime2 |
(3) |
datetime1 < datetime2 |
Compares datetime to
datetime. (4) |
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 member 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 member 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 member,
the tzinfo members 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 members, 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 both comparands are aware, and have the same tzinfo member, the
common tzinfo member is ignored and the base datetimes are compared. If
both comparands are aware and have different tzinfo members, the
comparands are first adjusted by subtracting their UTC offsets (obtained from
self.utcoffset()).
Note
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.
Instance methods:
-
datetime.date()
- Return date object with same year, month and day.
-
datetime.time()
- Return time object with same hour, minute, second and microsecond.
tzinfo is None. See also method timetz().
-
datetime.timetz()
- Return time object with same hour, minute, second, microsecond, and
tzinfo members. See also method time().
-
datetime.replace([year[, month[, day[, hour[, minute[, second[, microsecond[, tzinfo]]]]]]]])
- Return a datetime with the same members, except for those members 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 members.
-
datetime.astimezone(tz)
Return a datetime object with new tzinfo member tz, adjusting
the date and time members so the result is the same UTC time as self, but in
tz‘s local time.
tz must be an instance of a tzinfo subclass, and its
utcoffset() and dst() methods must not return None. self must
be aware (self.tzinfo must not be None, and self.utcoffset() must
not return None).
If self.tzinfo is tz, self.astimezone(tz) is equal to self: no
adjustment of date or time members is performed. Else the result is local time
in time zone tz, representing the same UTC time as self: after astz =
dt.astimezone(tz), astz - astz.utcoffset() will usually have the same date
and time members as dt - dt.utcoffset(). The discussion of class
tzinfo explains the cases at Daylight Saving Time transition boundaries
where this cannot be achieved (an issue only if tz models both standard and
daylight time).
If you merely want to attach a time zone object tz to a datetime dt without
adjustment of date and time members, 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 members, 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:
def astimezone(self, tz):
if self.tzinfo is tz:
return self
# Convert self to UTC, and attach the new time zone object.
utc = (self - self.utcoffset()).replace(tzinfo=tz)
# Convert from UTC to tz's local time.
return tz.fromutc(utc)
-
datetime.utcoffset()
- 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.
-
datetime.dst()
- 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.
-
datetime.tzname()
- 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,
-
datetime.timetuple()
- 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(), d.toordinal() - date(d.year, 1,
1).toordinal() + 1, dst)) 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.
-
datetime.utctimetuple()
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 the result’s
tm_year member may be MINYEAR-1 or MAXYEAR+1, if
d.year was MINYEAR or MAXYEAR and UTC adjustment spills over a year
boundary.
-
datetime.toordinal()
- Return the proleptic Gregorian ordinal of the date. The same as
self.date().toordinal().
-
datetime.weekday()
- 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().
-
datetime.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().
-
datetime.isocalendar()
- Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The same as
self.date().isocalendar().
-
datetime.isoformat([sep])
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,
>>> from datetime import tzinfo, timedelta, datetime
>>> class TZ(tzinfo):
... def utcoffset(self, dt): return timedelta(minutes=-399)
...
>>> datetime(2002, 12, 25, tzinfo=TZ()).isoformat(' ')
'2002-12-25 00:00:00-06:39'
-
datetime.__str__()
- For a datetime instance d, str(d) is equivalent to
d.isoformat(' ').
-
datetime.ctime()
- 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. See section strftime() Behavior.
Examples of working with datetime objects:
>>> from datetime import datetime, date, time
>>> # Using datetime.combine()
>>> d = date(2005, 7, 14)
>>> t = time(12, 30)
>>> datetime.combine(d, t)
datetime.datetime(2005, 7, 14, 12, 30)
>>> # Using datetime.now() or datetime.utcnow()
>>> datetime.now()
datetime.datetime(2007, 12, 6, 16, 29, 43, 79043) # GMT +1
>>> datetime.utcnow()
datetime.datetime(2007, 12, 6, 15, 29, 43, 79060)
>>> # Using datetime.strptime()
>>> dt = datetime.strptime("21/11/06 16:30", "%d/%m/%y %H:%M")
>>> dt
datetime.datetime(2006, 11, 21, 16, 30)
>>> # Using datetime.timetuple() to get tuple of all attributes
>>> tt = dt.timetuple()
>>> for it in tt:
... print it
...
2006 # year
11 # month
21 # day
16 # hour
30 # minute
0 # second
1 # weekday (0 = Monday)
325 # number of days since 1st January
-1 # dst - method tzinfo.dst() returned None
>>> # Date in ISO format
>>> ic = dt.isocalendar()
>>> for it in ic:
... print it
...
2006 # ISO year
47 # ISO week
2 # ISO weekday
>>> # Formatting datetime
>>> dt.strftime("%A, %d. %B %Y %I:%M%p")
'Tuesday, 21. November 2006 04:30PM'
Using datetime with tzinfo:
>>> from datetime import timedelta, datetime, tzinfo
>>> class GMT1(tzinfo):
... def __init__(self): # DST starts last Sunday in March
... d = datetime(dt.year, 4, 1) # ends last Sunday in October
... self.dston = d - timedelta(days=d.weekday() + 1)
... d = datetime(dt.year, 11, 1)
... self.dstoff = d - timedelta(days=d.weekday() + 1)
... def utcoffset(self, dt):
... return timedelta(hours=1) + self.dst(dt)
... def dst(self, dt):
... if self.dston <= dt.replace(tzinfo=None) < self.dstoff:
... return timedelta(hours=1)
... else:
... return timedelta(0)
... def tzname(self,dt):
... return "GMT +1"
...
>>> class GMT2(tzinfo):
... def __init__(self):
... d = datetime(dt.year, 4, 1)
... self.dston = d - timedelta(days=d.weekday() + 1)
... d = datetime(dt.year, 11, 1)
... self.dstoff = d - timedelta(days=d.weekday() + 1)
... def utcoffset(self, dt):
... return timedelta(hours=1) + self.dst(dt)
... def dst(self, dt):
... if self.dston <= dt.replace(tzinfo=None) < self.dstoff:
... return timedelta(hours=2)
... else:
... return timedelta(0)
... def tzname(self,dt):
... return "GMT +2"
...
>>> gmt1 = GMT1()
>>> # Daylight Saving Time
>>> dt1 = datetime(2006, 11, 21, 16, 30, tzinfo=gmt1)
>>> dt1.dst()
datetime.timedelta(0)
>>> dt1.utcoffset()
datetime.timedelta(0, 3600)
>>> dt2 = datetime(2006, 6, 14, 13, 0, tzinfo=gmt1)
>>> dt2.dst()
datetime.timedelta(0, 3600)
>>> dt2.utcoffset()
datetime.timedelta(0, 7200)
>>> # Convert datetime to another time zone
>>> dt3 = dt2.astimezone(GMT2())
>>> dt3 # doctest: +ELLIPSIS
datetime.datetime(2006, 6, 14, 14, 0, tzinfo=<GMT2 object at 0x...>)
>>> dt2 # doctest: +ELLIPSIS
datetime.datetime(2006, 6, 14, 13, 0, tzinfo=<GMT1 object at 0x...>)
>>> dt2.utctimetuple() == dt3.utctimetuple()
True
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[, minute[, second[, microsecond[, tzinfo]]]])
All arguments are optional. tzinfo may be None, or an instance of a
tzinfo subclass. The remaining arguments may be ints or longs, in the
following ranges:
- 0 <= hour < 24
- 0 <= minute < 60
- 0 <= second < 60
- 0 <= microsecond < 1000000.
If an argument outside those ranges is given, ValueError is raised. All
default to 0 except tzinfo, which defaults to None.
Class attributes:
-
time.min
- The earliest representable time, time(0, 0, 0, 0).
-
time.max
- The latest representable time, time(23, 59, 59, 999999).
-
time.resolution
- 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):
-
time.hour
- In range(24).
-
time.minute
- In range(60).
-
time.second
- In range(60).
-
time.microsecond
- In range(1000000).
-
time.tzinfo
- The object passed as the tzinfo argument to the time constructor, or
None if none was passed.
Supported operations:
- 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 both comparands are aware, and have
the same tzinfo member, the common tzinfo member is ignored and
the base times are compared. If both comparands are aware and have different
tzinfo members, 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.
- hash, use as dict key
- efficient pickling
- in Boolean contexts, a time object is considered to be true if and
only if, after converting it to minutes and subtracting utcoffset() (or
0 if that’s None), the result is non-zero.
Instance methods:
-
time.replace([hour[, minute[, second[, microsecond[, tzinfo]]]]])
- Return a time with the same value, except for those members 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 members.
-
time.isoformat()
- Return a string representing the time in ISO 8601 format, HH:MM:SS.mmmmmm or, if
self.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
-
time.__str__()
- 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 section strftime() Behavior.
-
time.utcoffset()
- 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.
-
time.dst()
- 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.
-
time.tzname()
- 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.
Example:
>>> from datetime import time, tzinfo
>>> class GMT1(tzinfo):
... def utcoffset(self, dt):
... return timedelta(hours=1)
... def dst(self, dt):
... return timedelta(0)
... def tzname(self,dt):
... return "Europe/Prague"
...
>>> t = time(12, 10, 30, tzinfo=GMT1())
>>> t # doctest: +ELLIPSIS
datetime.time(12, 10, 30, tzinfo=<GMT1 object at 0x...>)
>>> gmt = GMT1()
>>> t.isoformat()
'12:10:30+01:00'
>>> t.dst()
datetime.timedelta(0)
>>> t.tzname()
'Europe/Prague'
>>> t.strftime("%H:%M:%S %Z")
'12:10:30 Europe/Prague'
tzinfo is an abstract base clase, 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 does not supply
any concrete subclasses of tzinfo.
An instance of (a concrete subclass of) tzinfo can be passed to the
constructors for datetime and time objects. The latter objects
view their members 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(self, 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:
return CONSTANT # fixed-offset class
return CONSTANT + self.dst(dt) # daylight-aware class
If utcoffset() does not return None, dst() should not return
None either.
The default implementation of utcoffset() raises
NotImplementedError.
-
tzinfo.dst(self, dt)
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
member’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:
tz.utcoffset(dt) - tz.dst(dt)
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:
def dst(self):
# a fixed-offset class: doesn't account for DST
return timedelta(0)
or
def dst(self):
# Code to set dston and dstoff to the time zone's DST
# transition times based on the input dt.year, and expressed
# in standard local time. Then
if dston <= dt.replace(tzinfo=None) < dstoff:
return timedelta(hours=1)
else:
return timedelta(0)
The default implementation of dst() raises NotImplementedError.
-
tzinfo.tzname(self, 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(self, dt)
This is called from the default datetime.astimezone() implementation.
When called from that, dt.tzinfo is self, and dt‘s date and time members
are to be viewed as expressing a UTC time. The purpose of fromutc() is to
adjust the date and time members, 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:
def fromutc(self, dt):
# raise ValueError error if dt.tzinfo is not self
dtoff = dt.utcoffset()
dtdst = dt.dst()
# raise ValueError if dtoff is None or dtdst is None
delta = dtoff - dtdst # this is self's standard offset
if delta:
dt += delta # convert to standard local time
dtdst = dt.dst()
# raise ValueError if dtdst is None
if dtdst:
return dt + dtdst
else:
return dt
Example tzinfo classes:
from datetime import tzinfo, timedelta, datetime
ZERO = timedelta(0)
HOUR = timedelta(hours=1)
# A UTC class.
class UTC(tzinfo):
"""UTC"""
def utcoffset(self, dt):
return ZERO
def tzname(self, dt):
return "UTC"
def dst(self, dt):
return ZERO
utc = UTC()
# A class building tzinfo objects for fixed-offset time zones.
# Note that FixedOffset(0, "UTC") is a different way to build a
# UTC tzinfo object.
class FixedOffset(tzinfo):
"""Fixed offset in minutes east from UTC."""
def __init__(self, offset, name):
self.__offset = timedelta(minutes = offset)
self.__name = name
def utcoffset(self, dt):
return self.__offset
def tzname(self, dt):
return self.__name
def dst(self, dt):
return ZERO
# A class capturing the platform's idea of local time.
import time as _time
STDOFFSET = timedelta(seconds = -_time.timezone)
if _time.daylight:
DSTOFFSET = timedelta(seconds = -_time.altzone)
else:
DSTOFFSET = STDOFFSET
DSTDIFF = DSTOFFSET - STDOFFSET
class LocalTimezone(tzinfo):
def utcoffset(self, dt):
if self._isdst(dt):
return DSTOFFSET
else:
return STDOFFSET
def dst(self, dt):
if self._isdst(dt):
return DSTDIFF
else:
return ZERO
def tzname(self, dt):
return _time.tzname[self._isdst(dt)]
def _isdst(self, dt):
tt = (dt.year, dt.month, dt.day,
dt.hour, dt.minute, dt.second,
dt.weekday(), 0, -1)
stamp = _time.mktime(tt)
tt = _time.localtime(stamp)
return tt.tm_isdst > 0
Local = LocalTimezone()
# A complete implementation of current DST rules for major US time zones.
def first_sunday_on_or_after(dt):
days_to_go = 6 - dt.weekday()
if days_to_go:
dt += timedelta(days_to_go)
return dt
# US DST Rules
#
# This is a simplified (i.e., wrong for a few cases) set of rules for US
# DST start and end times. For a complete and up-to-date set of DST rules
# and timezone definitions, visit the Olson Database (or try pytz):
# http://www.twinsun.com/tz/tz-link.htm
# http://sourceforge.net/projects/pytz/ (might not be up-to-date)
#
# In the US, since 2007, DST starts at 2am (standard time) on the second
# Sunday in March, which is the first Sunday on or after Mar 8.
DSTSTART_2007 = datetime(1, 3, 8, 2)
# and ends at 2am (DST time; 1am standard time) on the first Sunday of Nov.
DSTEND_2007 = datetime(1, 11, 1, 1)
# From 1987 to 2006, DST used to start at 2am (standard time) on the first
# Sunday in April and to end at 2am (DST time; 1am standard time) on the last
# Sunday of October, which is the first Sunday on or after Oct 25.
DSTSTART_1987_2006 = datetime(1, 4, 1, 2)
DSTEND_1987_2006 = datetime(1, 10, 25, 1)
# From 1967 to 1986, DST used to start at 2am (standard time) on the last
# Sunday in April (the one on or after April 24) and to end at 2am (DST time;
# 1am standard time) on the last Sunday of October, which is the first Sunday
# on or after Oct 25.
DSTSTART_1967_1986 = datetime(1, 4, 24, 2)
DSTEND_1967_1986 = DSTEND_1987_2006
class USTimeZone(tzinfo):
def __init__(self, hours, reprname, stdname, dstname):
self.stdoffset = timedelta(hours=hours)
self.reprname = reprname
self.stdname = stdname
self.dstname = dstname
def __repr__(self):
return self.reprname
def tzname(self, dt):
if self.dst(dt):
return self.dstname
else:
return self.stdname
def utcoffset(self, dt):
return self.stdoffset + self.dst(dt)
def dst(self, dt):
if dt is None or dt.tzinfo is None:
# An exception may be sensible here, in one or both cases.
# It depends on how you want to treat them. The default
# fromutc() implementation (called by the default astimezone()
# implementation) passes a datetime with dt.tzinfo is self.
return ZERO
assert dt.tzinfo is self
# Find start and end times for US DST. For years before 1967, return
# ZERO for no DST.
if 2006 < dt.year:
dststart, dstend = DSTSTART_2007, DSTEND_2007
elif 1986 < dt.year < 2007:
dststart, dstend = DSTSTART_1987_2006, DSTEND_1987_2006
elif 1966 < dt.year < 1987:
dststart, dstend = DSTSTART_1967_1986, DSTEND_1967_1986
else:
return ZERO
start = first_sunday_on_or_after(dststart.replace(year=dt.year))
end = first_sunday_on_or_after(dstend.replace(year=dt.year))
# Can't compare naive to aware objects, so strip the timezone from
# dt first.
if start <= dt.replace(tzinfo=None) < end:
return HOUR
else:
return ZERO
Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
Central = USTimeZone(-6, "Central", "CST", "CDT")
Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")
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 first Sunday in April, and ends the minute after
1:59 (EDT) on the last Sunday in October:
UTC 3:MM 4:MM 5:MM 6:MM 7:MM 8:MM
EST 22:MM 23:MM 0:MM 1:MM 2:MM 3:MM
EDT 23:MM 0:MM 1:MM 2:MM 3:MM 4:MM
start 22:MM 23:MM 0:MM 1:MM 3:MM 4:MM
end 23:MM 0:MM 1:MM 1:MM 2:MM 3:MM
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. In order for astimezone() to make this guarantee, the
rzinfo.dst() method must consider times in the “missing hour” (2:MM for
Eastern) to be in daylight time.
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. In order for
astimezone() to make this guarantee, the tzinfo.dst() method must
consider times in the “repeated hour” to be in standard time. This is easily
arranged, as in the example, by expressing DST switch times in the time zone’s
standard local time.
Applications that can’t bear such ambiguities should avoid using hybrid
tzinfo subclasses; there are no ambiguities when using UTC, 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)).
strftime() 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.
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 0 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.
time and datetime objects support a %f format code
which expands to the number of microseconds in the object, zero-padded on
the left to six places.
New in version 2.6.
For a naive object, the %z and %Z format codes are replaced by empty
strings.
For an aware object:
- %z
- utcoffset() is transformed into a 5-character string of the 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(hours=-3, minutes=-30), %z is
replaced with the string '-0330'.
- %Z
- If tzname() returns None, %Z is replaced by an empty string.
Otherwise %Z is replaced by the returned value, which must be a string.
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.
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.
The exact range of years for which strftime() works also varies across
platforms. Regardless of platform, years before 1900 cannot be used.
Directive |
Meaning |
Notes |
%a |
Locale’s abbreviated weekday
name. |
|
%A |
Locale’s full weekday name. |
|
%b |
Locale’s abbreviated month
name. |
|
%B |
Locale’s full month name. |
|
%c |
Locale’s appropriate date and
time representation. |
|
%d |
Day of the month as a decimal
number [01,31]. |
|
%f |
Microsecond as a decimal
number [0,999999], zero-padded
on the left |
(1) |
%H |
Hour (24-hour clock) as a
decimal number [00,23]. |
|
%I |
Hour (12-hour clock) as a
decimal number [01,12]. |
|
%j |
Day of the year as a decimal
number [001,366]. |
|
%m |
Month as a decimal number
[01,12]. |
|
%M |
Minute as a decimal number
[00,59]. |
|
%p |
Locale’s equivalent of either
AM or PM. |
(2) |
%S |
Second as a decimal number
[00,61]. |
(3) |
%U |
Week number of the year
(Sunday as the first day of
the week) as a decimal number
[00,53]. All days in a new
year preceding the first
Sunday are considered to be in
week 0. |
(4) |
%w |
Weekday as a decimal number
[0(Sunday),6]. |
|
%W |
Week number of the year
(Monday as the first day of
the week) as a decimal number
[00,53]. All days in a new
year preceding the first
Monday are considered to be in
week 0. |
(4) |
%x |
Locale’s appropriate date
representation. |
|
%X |
Locale’s appropriate time
representation. |
|
%y |
Year without century as a
decimal number [00,99]. |
|
%Y |
Year with century as a decimal
number. |
|
%z |
UTC offset in the form +HHMM
or -HHMM (empty string if the
the object is naive). |
(5) |
%Z |
Time zone name (empty string
if the object is naive). |
|
%% |
A literal '%' character. |
|
Notes:
- When used with the strptime() function, the %f directive
accepts from one to six digits and zero pads on the right. %f is
an extension to the set of format characters in the C standard.
- When used with the strptime() function, the %p directive only affects
the output hour field if the %I directive is used to parse the hour.
- The range really is 0 to 61; this accounts for leap seconds and the
(very rare) double leap seconds.
- When used with the strptime() function, %U and %W are only used in
calculations when the day of the week and the year are specified.
- For example, if utcoffset() returns timedelta(hours=-3, minutes=-30),
%z is replaced with the string '-0330'.
|