time() returns number of seconds since the epoch so to figure out if there is a difference of more than 12 hours all you have to do is check for the difference using seconds (12hours = 60*60*12). 

if ($current_time - $oldtime > 43200)
{
    print "There is > 12 hour difference\n";
}

[download]

If you need to do more complex date/time calculations you may benefit from the many date modules on CPAN.

In reply to Re: Time Difference by duct_tape
in thread Time Difference by kpaxian25

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