Kindly follow the Steps below to set common time zone for all user profile
Note : We strongly recommend to take a backup before executing any update query.
* Run the below query to fetch the current time zones available under Servicedeskplus-MSP. ( Report -> New Query Report). Choose the preferred timezoneid which needs to be applied to all the users
select * from timezonedefinition;
* Kindly stop the application service.
* Replace the timezone ID in below query.
update sduserprofile set timezoneid=<timezoneid>;
* Restart the application service and verify the status.