Timezones of DateTime instances are ignored when persisting dates

When a DateTime instance, e.g. "2011-02-16 00:00:00 America/New_York" is written into the DB, the timezone is ignored and only "2011-02-16" is persisted. When fetching the date, it is written into a DateTime with the server's timezone, resulting in for example "2011-02-16 00:00:00 Europe/Berlin" which is not correct!

To fix this issue, Doctrine should convert dates to the server's timezone (if their own timezone differs) before persisting them or before executing queries containing DateTime instances.