the world is divided into 24 time zones spaced at intervals of 15 degrees in longitude. The zones start at 0 with Greenwich. Within each time zone, the hour and minute of the day is defined to be the same. Time zones are usually specified by the number of hours they differ from GMT. EST is GMT 5 hours.

Posted by:Jason Pitsch

A former Fortune 100 executive who left the corporate world to found Professional Watches. He's obsessed with aesthetics, quality, precision, horology, and watch brands that transcend time. (Article archive.)