#!/usr/bin/perl
#this shows where you run out of seconds and the 
#signed 32 goes negative. 
$secs_non_leap = 60 * 60 * 24 * 365; # seconds per non-leap year 
$secs_leap = 60 * 60 * 24 * 366;     # seconds per leap year 

$secs =  hex "7FFFFFFF"; # max number a signed 32 can hold 

foreach $year (1970 .. 2040) {
$leap = $year % 4 ? 0 : 1;
$secs -= $leap ? $secs_leap : $secs_non_leap;
print "$year $secs\n";
}