As already commented in issue2551417 (sorry for that I hadn't seen there is a separate issue):

Concerning the different timezones in the logs: We may want to add a logging-timezone setting: If we're running several trackers with different timezones in a single server we may want the logging to be in a consistent timezone.

Not very urgent, though, because I think anyone hosting multiple sites will do so in a (u)wsgi server behind a webserver, so logging there is using other facilities that already generate consistent timestamps for log entries.