This class can be used to determine the server and the Web user machine time zone. It uses the PHP time and date functions to determine the server time zone, server time and GMT time. A Javascript can set a cookie with the time on the Web user machine. The class reads that cookie to determine the Web user machine timezone offset comparing the Web user machine time with GMT time, considering eventual day light savings time shifts. The class can also look up a MySQL database to retrieve time zone information.