In PSOhub each user can set their own respective time zone.
To do so, simply go to your Profile & Preferences. In the Personal Information tab, you will find a field Time Zone where you can select the time zone where you are located.
PSOhub will then leverage this time zone when retrieving the Outlook appointments of this user in the Timesheet Calendar.
Read also: Where is the Time zone of your organization in PSOhub.