There is an existing feature request on this topic with alot of user feedback information in it. You might want to add a like to that post & read their info.
Within Calendar and the days schedule it would be really helpful if it was possible to specify some additional timezones.
This is REALLY helpful when working with international teams, customers and individuals outside your timezone. As such GMAIL and Outlook only offer 1 extra TZ. Having the ability to add more than one would enable the user to see across multiple locations the time of meetings. This may not sound important but where a user is in a “border” time (e.g. 0700-0900 - kids to school…