We have just released new timezone auto-detection code to the website and apps. It will automatically sync your timezone year-round (hopefully). The reason I say hopefully is there are strong limitations on what we can obtain from within a web browser. I've done my best to account for all scenarios and try to get the most accurate timezone possible.
This change was needed because the old mechanism was not 100% reliable at determining the appropriate DST (Daylight Savings Time) settings. Some users in some regions were having inaccurate race times listed in-game as a result. The new technique works around this and should give these users accurate race times.
Also, apologies for the disruption this caused when it was launched into the service!