Set the timezone at the top of the script, and all date/time functions
will then use that timezone anywhere else in the script.
Set timezone, and the list of timezone cities to use ...
Also, if it were me, I would simple write the UNIX timestamp (integer) into the column.
That would allow you to later display it any way you wish, down to the seconds.
Which is at this value when I submitted this: 1296840028
Later, you redisplay it like this:
echo date("h:i A", $timestamp);