=encoding utf8
=head1 NAME
POSIX::1003::Time - POSIX handling time
=head1 SYNOPSIS
use POSIX::1003::Time;
tzset(); # set-up local timezone from $ENV{TZ}
($std, $dst) = tzname; # timezone abbreviations
$str = ctime($timestamp); # is equivalent to:
$str = asctime(localtime($timestamp))
$str = strftime("%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2);
# $str contains "Tuesday, December 12, 1995"
$timestamp = mktime(0, 30, 10, 12, 11, 95);
print "Date = ", ctime($timestamp);
print scalar localtime;
my $year = (localtime)[5] + 1900;
$timespan = difftime($end, $begin);
=head1 DESCRIPTION
=head1 FUNCTIONS
=head2 Standard POSIX
B<Warning:> the functions L<asctime()|POSIX::1003::Time/"Standard POSIX">, L<mktime()|POSIX::1003::Time/"Standard POSIX">, and L<strftime()|POSIX::1003::Time/"Standard POSIX">
share a weird complex encoding with L<localtime()|POSIX::1003::Time/"Standard POSIX"> and L<gmtime()|POSIX::1003::Time/"Standard POSIX">:
the month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at
zero. I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0,
not 1. The year (C<year>) is given in years since 1900. I.e., the year
1995 is 95; the year 2001 is 101.
=over 4
=item B<asctime>(SEC, MIN, HOUR, MDAY, MON, YEAR, ...)
The C<asctime> function uses C<strftime> with a fixed format, to produce
timestamps with a trailing new-line. Example:
"Sun Sep 16 01:03:52 1973\n"
The parameter order is the same as for L<strftime()|POSIX::1003::Time/"Standard POSIX"> without the C<$fmt>:
my $str = asctime($sec, $min, $hour, $mday, $mon, $year,
$wday, $yday, $isdst);
=item B<clock>()
The amount of spent processor time in microseconds.
=item B<ctime>(TIMESTAMP)
# equivalent
my $str = ctime $timestamp;
my $str = asctime localtime $timestamp;
=item B<difftime>(TIMESTAMP, TIMESTAMP)
Difference between two TIMESTAMPs, which are floats.
$timespan = difftime($end, $begin);
=item B<gmtime>([TIME])
Simply L<perlfunc/gmtime>
=item B<localtime>([TIME])
Simply L<perlfunc/localtime>
=item B<mktime>(SEC, MIN, HOUR, MDAY, MON, YEAR, ...)
Convert date/time info to a calendar time.
Returns "undef" on failure.
my $t = mktime(sec, min, hour, mday, mon, year,
wday = 0, yday = 0, isdst = -1)
# Calendar time for December 12, 1995, at 10:30 am
$timestamp = mktime(0, 30, 10, 12, 11, 95);
print "Date = ", ctime($time_t);
=item B<strftime>(FMT, SEC, MIN, HOUR, MDAY, MON, YEAR, ...)
The formatting of C<strftime> is extremely flexible but the parameters
are quite tricky. Read carefully!
my $str = strftime($fmt, $sec, $min, $hour,
$mday, $mon, $year, $wday, $yday, $isdst);
If you want your code to be portable, your format (FMT) argument
should use only the conversion specifiers defined by the ANSI C
standard (C89, to play safe). These are C<aAbBcdHIjmMpSUwWxXyYZ%>.
But even then, the results of some of the conversion specifiers are
non-portable.
=item B<tzname>()
Returns the strings to be used to represent Standard time (STD)
respectively Daylight Savings Time (DST).
tzset();
my ($std, $dst) = tzname;
=item B<tzset>()
Set-up local timezone from C<$ENV{TZ}> and the OS.
=back
=head1 CONSTANTS
=head2 Constants from time.h
CLK_TCK CLOCKS_PER_SEC NULL
=head2 Constants from limits.h
TXNAME_MAX
=head1 SEE ALSO
This module is part of POSIX-1003 distribution version 0.94_1,
built on May 16, 2013. Website: F<http://perl.overmeer.net>. The code is based on L<POSIX>, which
is released with Perl itself. See also L<POSIX::Util> for
additional functionality.
=head1 COPYRIGHTS
Copyrights 2011-2013 on the perl code and the related documentation
by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See F<http://www.perl.com/perl/misc/Artistic.html>