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strftime(3)              BSD Library Functions Manual              strftime(3)


NAME

     strftime, strftime_l -- format date and time


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <time.h>

     size_t
     strftime(char *restrict s, size_t maxsize, const char *restrict format,
         const struct tm *restrict timeptr);

     #include <time.h>
     #include <xlocale.h>

     size_t
     strftime_l(char *restrict s, size_t maxsize, const char *restrict format,
         const struct tm *restrict timeptr, locale_t loc);


DESCRIPTION

     The strftime() function formats the information from timeptr into the
     buffer s, according to the string pointed to by format.

     The format string consists of zero or more conversion specifications and
     ordinary characters.  All ordinary characters are copied directly into
     the buffer.  A conversion specification consists of a percent sign
     ```%''' and one other character.

     No more than maxsize characters will be placed into the array.  If the
     total number of resulting characters, including the terminating NUL char-
     acter, is not more than maxsize, strftime() returns the number of charac-
     ters in the array, not counting the terminating NUL.  Otherwise, zero is
     returned and the buffer contents are indeterminate.

     Although the strftime() function uses the current locale, the
     strftime_l() function may be passed a locale directly. See xlocale(3) for
     more information.

     The conversion specifications are copied to the buffer after expansion as
     follows:-

     %A    is replaced by national representation of the full weekday name.

     %a    is replaced by national representation of the abbreviated weekday
           name.

     %B    is replaced by national representation of the full month name.

     %b    is replaced by national representation of the abbreviated month
           name.

     %C    is replaced by (year / 100) as decimal number; single digits are
           preceded by a zero.

     %c    is replaced by national representation of time and date.

     %D    is equivalent to ``%m/%d/%y''.

     %d    is replaced by the day of the month as a decimal number (01-31).

     %E* %O*
           POSIX locale extensions.  The sequences %Ec %EC %Ex %EX %Ey %EY %Od
           %Oe %OH %OI %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy are supposed to
           provide alternate representations.

           Additionally %OB implemented to represent alternative months names
           (used standalone, without day mentioned).

     %e    is replaced by the day of the month as a decimal number (1-31);
           single digits are preceded by a blank.

     %F    is equivalent to ``%Y-%m-%d''.

     %G    is replaced by a year as a decimal number with century.  This year
           is the one that contains the greater part of the week (Monday as
           the first day of the week).

     %g    is replaced by the same year as in ``%G'', but as a decimal number
           without century (00-99).

     %H    is replaced by the hour (24-hour clock) as a decimal number
           (00-23).

     %h    the same as %b.

     %I    is replaced by the hour (12-hour clock) as a decimal number
           (01-12).

     %j    is replaced by the day of the year as a decimal number (001-366).

     %k    is replaced by the hour (24-hour clock) as a decimal number (0-23);
           single digits are preceded by a blank.

     %l    is replaced by the hour (12-hour clock) as a decimal number (1-12);
           single digits are preceded by a blank.

     %M    is replaced by the minute as a decimal number (00-59).

     %m    is replaced by the month as a decimal number (01-12).

     %n    is replaced by a newline.

     %O*   the same as %E*.

     %p    is replaced by national representation of either "ante meridiem"
           (a.m.)  or "post meridiem" (p.m.)  as appropriate.

     %R    is equivalent to ``%H:%M''.

     %r    is equivalent to ``%I:%M:%S %p''.

     %S    is replaced by the second as a decimal number (00-60).

     %s    is replaced by the number of seconds since the Epoch, UTC (see
           mktime(3)).

     %T    is equivalent to ``%H:%M:%S''.

     %t    is replaced by a tab.

     %U    is replaced by the week number of the year (Sunday as the first day
           of the week) as a decimal number (00-53).

     %u    is replaced by the weekday (Monday as the first day of the week) as
           a decimal number (1-7).

     %V    is replaced by the week number of the year (Monday as the first day
           of the week) as a decimal number (01-53).  If the week containing
           January 1 has four or more days in the new year, then it is week 1;
           otherwise it is the last week of the previous year, and the next
           week is week 1.

     %v    is equivalent to ``%e-%b-%Y''.

     %W    is replaced by the week number of the year (Monday as the first day
           of the week) as a decimal number (00-53).

     %w    is replaced by the weekday (Sunday as the first day of the week) as
           a decimal number (0-6).

     %X    is replaced by national representation of the time.

     %x    is replaced by national representation of the date.

     %Y    is replaced by the year with century as a decimal number.

     %y    is replaced by the year without century as a decimal number
           (00-99).

     %Z    is replaced by the time zone name.

     %z    is replaced by the time zone offset from UTC; a leading plus sign
           stands for east of UTC, a minus sign for west of UTC, hours and
           minutes follow with two digits each and no delimiter between them
           (common form for RFC 822 date headers).

     %+    is replaced by national representation of the date and time (the
           format is similar to that produced by date(1)).

     %-*   GNU libc extension.  Do not do any padding when performing numeri-
           cal outputs.

     %_*   GNU libc extension.  Explicitly specify space for padding.

     %0*   GNU libc extension.  Explicitly specify zero for padding.

     %%    is replaced by `%'.


SEE ALSO

     date(1), printf(1), ctime(3), printf(3), strptime(3), wcsftime(3),
     xlocale(3)


STANDARDS

     The strftime() function conforms to ISO/IEC 9899:1990 (``ISO C90'') with
     a lot of extensions including `%C', `%D', `%E*', `%e', `%G', `%g', `%h',
     `%k', `%l', `%n', `%O*', `%R', `%r', `%s', `%T', `%t', `%u', `%V', `%z',
     and `%+'.

     The peculiar week number and year in the replacements of `%G', `%g', and
     `%V' are defined in ISO 8601: 1988.


BUGS

     There is no conversion specification for the phase of the moon.

     The strftime() function does not correctly handle multibyte characters in
     the format argument.

BSD                            November 4, 2004                            BSD

Mac OS X 10.8 - Generated Fri Aug 31 05:49:19 CDT 2012