From Astro Wars
The time difference between your local time and the server can be selected in the Settings page of the News Screen. You should ensure your local time is displayed correctly at the top of the Settings page once the time difference is set. This is important when launching fleets (including the use of the Arrival Time Calculator), for seeing the correct time in News Alerts such as attacking fleet arrival times, and showing the correct time in the browser title bar each time you open a game page. Once set, all times displayed in your news screen will be GMT (Greenwich Mean Time) +/- the difference you entered for your time zone, for the current and all future rounds until you change it again.
You often need precision timing for coordinated attacks or for defending speed attacks, so here is a useful free download: Atomic Clock, which pings the US military timebases then corrects your system clock.
Note: for Daylight Saving Time, you must manually adjust the difference between server time and local time. In this game, Daylight Saving Time begins the last Sunday of March at 01:00 GMT and ends the last Sunday in October at 02:00 GMT.