Eastern Time (ET) is a time zone that is 5 hours behind Coordinated Universal Time (UTC-5). It is used in several regions of the United States, including major cities like New York and Washington, D.C.. During Daylight Saving Time, which typically runs from the second Sunday in March to the first Sunday in November, Eastern Time shifts to Eastern Daylight Time (EDT), which is UTC-4. Eastern Time is one of the most populous time zones in North America and serves as a reference point for other time zones. It is important for scheduling events, broadcasting, and business operations, especially for industries that operate across multiple regions, such as television and finance.