Display user analytics according to instance server date/time

Created by: christinelovett

Currently our analytics displays to the user against our timetable, this creates confusion over user statistics of those sourcegraph instances hosted in different timezones.

Admins are seeing activity on days when there are no active users.

https://app.hubspot.com/contacts/2762526/company/1749054227 would like their usage statistics to display according to their server date/time