If we use SSO , then we can set model user's time zone whatever we want to default for the new operators, however, existing operators also need to change the timezone. Admins can change manually in their operators profile. However, we would like to give the users an ability to change their timezone as they travel to different timezone. And if there is a best practice on your question:
"how can we give users a control to change their timezone while they be in another timezone?"