Has no one even looked at the source yet? Hmm. Well, if you'd look at it, in the javascript there's a comment:
/* REDIR UNTIL USER/SERVER SYNC */
Just after they set up the actual clock (as far as I can tell, I've never learned javascript). Not sure why they'd use the phrase "redir", but I'm pretty sure that'd be the code that refreshes it and syncs it with server time when the counter hits 0 after you change your computer clock. Not much else to find, unless it's in the script.
Dritz's recent comments: