SitePoint PHP Blog: How To Synchronize Your PHP and MySQL Timezones
In a new post to the SitePoint PHP blog today Craig Buckler looks at a method for synchronizing your time between your PHP application and it's MySQL backend to make date handling a bit easier - no messy code-based timezone changes needed.
Many developers solve the problem by shifting all date/time responsibility to PHP. They may also convert dates to Unix timestamp integers for simpler handling, although you should be wary of the Y2K38 Bug.
They show a handy tip so you won't have to worry quite so much that relies on setting a "TIMEZONE" constant you can use to set the default timezone and a "time_zone" offset that can be used each time you make the connection to your database (or, alternatively, in a cron that keeps things up to date without interfering with performance).