I have implemented my own script for auctions. But my problem is how to handle time. Right now all auctions are based on UTC time, so whatever user's timezone is when he/she comes to site auction will start and end at the same time(UTC). I used date_default_timezone_set('UTC') to set default timezone throughout whole site.

But I guess that might be little bit confusing for users. Did anyone have similar problem and what could be the best solution for it.