Eastern Standard Time (or EST) is the time zone for parts of Canada, United States, Mexico and parts of South America. Eastern Standard Time is one hour ahead of Central Standard Time and three hours ahead of America's west coast, which is on Pacific Standard Time. EST is five hours behind Greenwich Mean Time. Most of the population of the United States lives in Eastern Standard Time.

In 2007, the United States Congress passed a law changing the dates of EDT to start at 2 am on the second Sunday of March and end at 2 am on the first Sunday of November. The change intended to decrease the amount of electricity used during evening hours in the Spring and Summer. Additionally, studies have shown that there are fewer motor vehicle accidents during Daylight Saving Time.

1. Ontario
2. Quebec

1. Connecticut
2. Delaware
3. Georgia
4. Maine
5. Maryland
6. Massachusetts
7. New Hampshire
8. New Jersey
9. New York
10. North Carolina
11. Ohio
12. Pennsylvania
13. Rhode Island
14. South Carolina
15. Vermont
16. Virginia
17. Washington DC
18. West Virginia

1. Quintana Roo

1. Panama

1. Jamaica
2. Haiti
3. Cuba
4. Bahamas

1. Colombia
2. Ecuador ( except Galapagos )
3. Peru
4. Brazil (parts)