#!/usr/bin/perl -sw

use strict;
use Benchmark;

our $ITERATIONS ||= 1e7;

timethese($ITERATIONS,
          {
           gmtime => sub {
             my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday) =
               gmtime(time);
           },
           localtime => sub {
             my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
               localtime(time);
           },
          }
         );

__END__

$ perl 619744.pl
Benchmark: timing 10000000 iterations of localtime, gmtime...
 localtime: 101 wallclock secs (51.07 usr + 45.89 sys = 96.96 CPU) @ 103135.31/s (n=10000000)
    gmtime: 62 wallclock secs (29.76 usr + 27.94 sys = 57.70 CPU) @ 173310.23/s (n=10000000)