This is the official support thread for this new mod.

This mod is available for download here: Time Zone Fix

This module allows you to set the Server PHP and MySql time zone to your local time zone in your Zen-Cart website, if you are in a situation where your store is in a different time zone from the server on which it is hosted. (For example, your store is based in Australia but is hosted on a server in the USA.)

This module replaces the previous Time Zone Offset mod.
Much simpler and overwrites only 1 core file.
When working it fixes all known Time Zone problems.