strftime#

Format a broken-down time as a string using a format template.

Synopsis#

use POSIX qw(strftime);
my @tm = localtime;
my $str = strftime("%Y-%m-%d %H:%M:%S", @tm);

What you get back#

A byte string formatted according to the template. Argument order matches localtime / gmtime: second, minute, hour, mday, mon (0-11), year (years since 1900), wday, yday, isdst - the last three optional and defaulting to -1.

Edge cases#

  • Fewer than seven arguments (format plus the first six tm fields): returns the empty string.

  • Output truncated at 1024 bytes.

  • Month is 0-11 and year is years-since-1900, the struct tm convention, not the 1-12 / 4-digit-year human convention.

  • $wday and $yday are accepted and IGNORED, as upstream ignores them. Both are derived from the date, so passing a wrong weekday cannot produce a wrong %A; passing none is the normal call.

  • Out-of-range fields normalise rather than being echoed back: month 12 is January of the following year.

Differences from upstream#

Fully compatible with upstream POSIX.

See also#

  • mktime - go the other way: broken-down time to epoch seconds.

  • asctime, ctime - simpler canned-format alternatives.