strftime(3) - NetBSD Manual Pages

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STRFTIME(3)               NetBSD Programmer's Manual               STRFTIME(3)


NAME

     strftime - format date and time


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <time.h>

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


DESCRIPTION

     The strftime() function formats the information from timeptr into the
     buffer buf 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 null
     character, is not more than maxsize, strftime() returns the number of
     characters in the array, not counting the terminating null.  Otherwise,
     zero is returned.

     Each conversion specification is replaced by the characters as follows
     which are then copied into the buffer.

     %A    is replaced by the locale's full weekday name.

     %a    is replaced by the locale's abbreviated weekday name.

     %B    is replaced by the locale's full month name.

     %b or %h
           is replaced by the locale's abbreviated month name.

     %C    is replaced by the century (a year divided by 100 and truncated to
           an integer) as a decimal number [00,99].

     %c    is replaced by the locale's appropriate date and time representa-
           tion.

     %D    is replaced by the date in the format ``%m/%d/%y''.

     %d    is replaced by the day of the month as a decimal number [01,31].

     %e    is replaced by the day of month as a decimal number [1,31]; single
           digits are preceded by a blank.

     %F    is replaced by the time in the format ``%Y-%m-%d'' (the ISO 8601
           date format).

     %G    is replaced by the ISO 8601 year with century as a decimal number.

     %g    is replaced by the ISO 8601 year without century as a decimal num-
           ber (00-99).  This is the year that includes the greater part of
           the week. (Monday as the first day of a week). See also the `%V'
           conversion specification.

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

     %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.

     %p    is replaced by the locale's equivalent of either ``AM'' or ``PM''.

     %R    is replaced by the time in the format ``%H:%M''.

     %r    is replaced by the locale's representation of 12-hour clock time
           using AM/PM notation.

     %S    is replaced by the second as a decimal number [00,61].

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

     %T    is replaced by the time in the format ``%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]. According to ISO 8601 the
           week containing January 1 is week 1 if it has four or more days in
           the new year, otherwise it is week 53 of the previous year, and the
           next week is week 1.  The year is given by the `%G' conversion
           specification.

     %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 the locale's appropriate time representation.

     %x    is replaced by the locale's appropriate date representation.

     %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 offset from ITC in the ISO 8601 format
           ``[-]hhmm''.

     %%    is replaced by `%'.


SEE ALSO

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


STANDARDS

     The strftime() function conforms to ISO/IEC 9899:1999 (``ISO C99'').  The
     `%C', `%D', `%e', `%g', `%G', `%h', `%k', `%l', `%n', `%r', `%R', `%s',
     `%t', `%T', `%u', and `%V' conversion specifications are extensions.


BUGS

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

NetBSD 1.6.2                     June 29, 1991                               3