Date moves 16 hours ahead when node saved

Any idea why when upon saving, the date on a calendar event node moves 16 hours ahead? From browsing the issues for this module, it seems possible that there's a PHP-related bug here—my client's host is running PHP 5.2.6. The date change so far is consistent, and none of the date/time settings seem out of whack.

I'm at a loss at this point. Usually the date/calendar/views combo pretty much works out of the box for me.