The only place where time zones come into play is when posting or updating your profile, articles, questions and answers.
Consider a professional in Attica publishing an article at 10:00am Athens/Greece time zone.
This same article will instantly appear on the screen of a user in Berlin as published at 9:00am Berlin/Germany time zone, which is exactly the same moment in time but in different time zones.
To change your time zone:
1
First login to your account.
2
Open Account dashboard page and go to Settings.
3
In the Time zone section select your preferred time zone and then Save to update your selection.