PAM GUI --> Settings --> Global Settings --> Default Preferences --> Time Zone Region
What does this Time Zone setting do and would it affect the system functionality?
The important thing is that the PAM server is timely synchronized.
If you have NTP server configured, PAM would be in time sync with GMT/UTC timestamp.
What the setting does is to display the logs in your configured timezone which would otherwise appear in UTC.
For example, if you select your Time Zone Region to Brazil, the log timestamps appearing in the PAM GUI would appear in Brazil local time.