Offset: EST is 5 hours behind Greenwich Mean Time (GMT) and is used in North America. Countries: It is used in following countries: Bahamas, Canada, Haiti, Jamaica, Cayman Islands, Mexico, Panama, Turks & Caicos Is, United States.How do you calculate GMT time?
Greenwich Mean Time is calculated from the Prime Meridian, which runs north and south through Greenwich, England. It's also home of the Royal Observatory. Since the Earth is round, there needs to be a notational line where things begin and end, and the Prime Meridian is it for time. Your GMT is either plus or minus the time at the Prime Meridian.What is the Eastern Time Zone in GMT?
Eastern Daylight Time is in the Eastern Time Zone of the United States of America (USA) and Canada. Eastern Standard Time (EST) is 5 hours behind Greenwich Mean Time (GMT-5).