I'm thinking there should be a Drupal on the edge series, featuring all the weird and wonderful problems you're never likely to encounter :)
Here's one of them, recently I've had to work with negative timestamps and Drupal, which as it happens doesn't support negative timestamps.
The issue is one more of PHP compatibility than Drupal, providing you're running PHP >= 5.1 all you need to do is apply the patch from the following d.org issue:
That's it! But to help you with whatever troubles you may have, I came across this very helpful post on how to convert dates to timestamps whilst keeping in mind negative timestamps, and vice versa:
http://www.epochconverter.com/programming/mysql-from-unixtime.php (See the heading "Negative epochs" on this page).