It's not an Epoch time bug, it's a lazy programmer bug. If you're going to use X time system, do so intelligently. If you're going to use Y time system... etc.
And Facebook uses PHP which does support checking the difference between NULL and 0: http://php.net/manual/en/types.comparisons.php [php.net] (look at the table of Strict comparisons with ===
and you see that as a good thing?
It's not an Epoch time bug, it's a lazy programmer bug. If you're going to use X time system, do so intelligently. If you're going to use Y time system... etc.
I don't understand people who prefer to use magic numbers over NULL, but there appear to be many.