strptime
—
converts a character string to a time value
Standard C Library (libc, -lc)
#include <time.h>
char *
strptime
(const
char * restrict buf,
const char * restrict
format, struct tm *
restrict tm);
The strptime
() function converts the character string
pointed to by buf to values which are stored in the
tm structure pointed to by tm,
using the format specified by format.
The format string consists of zero or more
conversion specifications, whitespace characters as defined by
isspace
(), and ordinary characters. All ordinary
characters in format are compared directly against the
corresponding characters in buf; comparisons which
fail will cause strptime
() to fail. Whitespace
characters in format match any number of whitespace
characters in buf, including none.
A conversion specification consists of a percent sign
‘%
’ followed by one or two conversion
characters which specify the replacement required. There must be white-space
or other non-alphanumeric characters between any two conversion
specifications.
Conversion of alphanumeric strings (such as month and weekday
names) is done without regard to case. Conversion specifications which
cannot be matched will cause strptime
() to fail.
The LC_TIME category defines the locale values for the conversion
specifications. The following conversion specifications are supported:
%a
- the day of week, using the locale's weekday names; either the abbreviated
or full name may be specified.
%A
- the same as
%a
.
%b
- the month, using the locale's month names; either the abbreviated or full
name may be specified.
%B
- the same as
%b
.
%c
- the date and time, using the locale's date and time format.
%C
- the century number [0,99]; leading zeros are permitted but not required.
This conversion should be used in conjunction with the %y conversion.
%d
- the day of month [1,31]; leading zeros are permitted but not
required.
%D
- the date as %m/%d/%y.
%e
- the same as
%d
.
%F
- the date as %Y-%m-%d (the ISO 8601 date format).
%g
- the year corresponding to the ISO week number, without the century. (A
NetBSD extension.)
%G
- the year corresponding to the ISO week number, with the century. (A
NetBSD extension.)
%h
- the same as
%b
.
%H
- the hour (24-hour clock) [0,23]; leading zeros are permitted but not
required.
%I
- the hour (12-hour clock) [1,12]; leading zeros are permitted but not
required.
%j
- the day number of the year [1,366]; leading zeros are permitted but not
required.
%k
- the same as
%H
.
%l
- the same as
%I
.
%m
- the month number [1,12]; leading zeros are permitted but not
required.
%M
- the minute [0,59]; leading zeros are permitted but not required.
%n
- any white-space, including none.
%p
- the locale's equivalent of a.m. or p.m.
%r
- the time (12-hour clock) with %p, using the locale's time format.
%R
- the time as %H:%M.
%S
- the seconds [0,60]; leading zeros are permitted but not required.
%s
- the number of seconds since the Epoch, UTC (see
mktime(3)). (A
NetBSD extension.)
%t
- any white-space, including none.
%T
- the time as %H:%M:%S.
%u
- the day of the week as a decimal number, where Monday = 1. (A
NetBSD extension.)
%U
- the week number of the year (Sunday as the first day of the week) as a
decimal number [0,53]; leading zeros are permitted but not required. All
days in a year preceding the first Sunday are considered to be in week
0.
%V
- the ISO 8601:1988 week number as a decimal number. If the week (starting
on Monday) that contains January 1 has more than three days in the new
year, then it is considered the first week of the year. If it has fewer
than four days in the new year, then it is considered the last week of the
previous year. Weeks are numbered from 1 to 53. (A
NetBSD extension.)
%w
- the weekday as a decimal number [0,6], with 0 representing Sunday; leading
zeros are permitted but not required.
%W
- the week number of the year (Monday as the first day of the week) as a
decimal number [0,53]; leading zeros are permitted but not required. All
days in a year preceding the first Monday are considered to be in week
0.
%x
- the date, using the locale's date format.
%X
- the time, using the locale's time format.
%y
- the year within the 20th century [69,99] or the 21st century [0,68];
leading zeros are permitted but not required. If specified in conjunction
with %C, specifies the year [0,99] within that century.
%Y
- the year, including the century (i.e., 1996).
%z
- an ISO 8601, RFC-2822, or RFC-3339 time zone specification. This is one of
the following:
- The offset from Coordinated Universal Time
(‘
UTC
’) specified as:
- [+-]hhmm
- [+-]hh:mm
- [+-]hh
- ‘
UTC
’ specified as:
- UTC (‘
Coordinated Universal
Time
’)
- GMT (‘
Greenwich Mean
Time
’)
- UT (‘
Universal Time
’)
- Z (‘
Zulu Time
’)
- A three character US time zone specified as:
- EDT
- EST
- CDT
- CST
- MDT
- MST
- PDT
- PST
with the first letter standing for
‘Eastern
’ (“E”),
‘Central
’ (“C”),
‘Mountain
’ (“M”)
or ‘Pacific
’
(“P”), and the second letter standing for
‘Daylight
’ (“D” or
summer) time or ‘Standard
’
(“S”) time
- a single letter military or nautical time zone specified as:
- “A” through “I”
- “K” through “Y”
- “J” (non-nautical local time zone)
- An arbitrary timezone name that can be loaded from the database.
(A NetBSD extension.)
%Z
- time zone name or no characters when time zone information is unavailable.
(A NetBSD extension.)
%%
- matches a literal `%'. No argument is converted.
For compatibility, certain conversion specifications can be modified by the
E
and O
modifier characters to
indicate that an alternative format or specification should be used rather
than the one normally used by the unmodified conversion specification. As
there are currently neither alternative formats nor specifications supported
by the system, the behavior will be as if the unmodified conversion
specification were used.
Case is ignored when matching string items in
buf, such as month and weekday names.
If successful, the strptime
() function returns a pointer
to the character following the last character parsed. Otherwise, a
NULL
pointer is returned.
The strptime
() function conforms to
X/Open Portability Guide Issue 4
(“XPG4”).
The %Z
format specifier only accepts time zone
abbreviations of the local time zone, or the values “GMT” or
“UTC”. This limitation is caused by the ambiguity of overloaded
time zone abbreviations, for example EST is both Eastern Standard Time and
Eastern Australia Summer Time.