Eastern Time Zone

1. Overview (Eastern Time Zone)

The Eastern Time Zone encompasses 17 US states in their entirety and also applies in parts of five additional US states. It is generally used as the dominant time in media and TV schedules, with most cable and national networks focusing on Eastern Time as a priority, and then mentioning other time zones afterwards. Outside of the US, the Eastern Time Zone is also in effect in large parts of Canada, one Mexican state, several Caribbean Islands and Panama in Central America. Some areas of South America also use the same time as the Eastern Time Zone.

2. History of Time Zones in the US

Time zones didn’t exist in the early years of the United States. Until the late 1800s, time would be told through the use of the sun. From town to town and state to state, people would look at the sun and wait until it crossed over the meridian to set their clocks to midday, and that’s how time was set all around the US. There were no norms or time zones or standards around the nation, which actually led to quite a few problems, especially as the United States started to grow and develop.

• Why was a standardized time system needed in the United States?
  • Before standard time zones, each town and station had its own local time, which made scheduling difficult.
  • With the expansion of the railroad network, the existing timekeeping system caused major problems for commuters and train schedules.
• What was the first time zone system in the U.S.?
  • The train authorities created their own system, dividing the nation into 100 different railroad time zones.
  • Although this helped organize train schedules, it remained complicated and inefficient.
• When were the four major U.S. time zones introduced?
  • In 1883, the United States decided to introduce four major time zones.
  • The continental U.S. was divided into:
  • Pacific Time Zone
  • Mountain Time Zone
  • Central Time Zone
  • Eastern Time Zone
  • Each zone was separated by one hour.
• How was the new time system implemented?
  • On November 18, 1883, telegraph messages were sent to major cities in each zone.
  • The messages instructed them on how to set their clocks to match the new system.
  • This marked the beginning of regulated timekeeping in the U.S.
• Were additional time zones added later?
  • Yes, additional time zones were later introduced for other states and territories, including:
  • Alaska
  • Samoa

3. Details of the Eastern Time Zone

The Eastern Time Zone (ET), like other US time zones, is divided into both a standard version, Eastern Standard Time (EST) and a daylight version, Eastern Daylight Time (EDT). The former is five hours behind Coordinated Universal Time (UTC), while the latter is just four hours behind UTC. Eastern Standard Time is used from November through to March, while Eastern Daylight Time is used for the other months of the year.

• Which states are entirely in the Eastern Time Zone?
  • Seventeen U.S. states are fully located within the Eastern Time Zone:
  • Connecticut
  • Georgia
  • Delaware
  • Maryland
  • Maine
  • New Hampshire
  • Massachusetts
  • New York
  • New Jersey
  • Pennsylvania
  • Ohio
  • North Carolina
  • South Carolina
  • Rhode Island
  • Vermont
  • Virginia
  • West Virginia
• Which states are partially in the Eastern Time Zone?
  • Five U.S. states are partially located within the Eastern Time Zone:
  • Florida
  • Indiana
  • Michigan
  • Kentucky
  • Tennessee

4. Daylight Savings Time in the Eastern Time Zone

All around the world, systems of daylight savings are used to save energy and adapt to the changing sunset and sunrise times in various locations throughout the year. The idea of daylight savings in the US had been around for a long time before being officially established in 1966 with the Uniform Time Act. In the Eastern Time Zone, this act meant that clocks would go back one hour to EDT on the first Sunday of April and forward on the last Sunday in October.

Decades later, in 2005, the Energy Policy Act changed the dates of daylight savings. Since then in the Eastern Time Zone, EDT is observed from the second Sunday of March through to the first Sunday of November. Daylight savings time is used throughout the Eastern Time Zone in both the US and Canada, while Mexico, the Caribbean Islands, and Central American areas each have their own rules and dates.