I\'m using the following INSERT statement:
INSERT INTO messages SET `to` = \'\".$to.\"\', `from` = \'\".$this->userid.\"\', `title` = \'\".$title.\"\', `m
After you open the connection to MySQL, run the following as a query:
SET time_zone = timezone;
Then all functions you do will run for that timezone for that connection (i.e. until you close the "link" to the database".
If you have the appropriate permissions you can lock it "permanently" / globaly. Tiemzone strings are standard strings as you have in your question.
http://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html