You need to set time zone manually (i.e. the controller does not detect time zone automatically. You can follow the online user manual to see how to set time zone.
Regarding the time drift: when you reboot the controller (assuming it can connect to the Internet), it should grab the current time (based on your time zone setting). If the time doesn’t get updated, you should check if your controller has a valid IP. Without a valid Internet connection, it cannot perform NTP time sync.