What is EST? (Eastern Standard Time)

EST is one of the most-quoted time zones on Earth because so many people, businesses and broadcasters sit inside it. But it is widely misused: for most of the year, the East Coast is not actually on EST at all.

What does EST stand for?

EST stands for Eastern Standard Time. "Standard" is the key word: it is the baseline, non-daylight-saving offset for the Eastern zone, set at UTC-5, meaning five hours behind Coordinated Universal Time. When it is 12:00 noon in London (UTC in winter), it is 7:00 AM in EST.

Where is EST used?

The Eastern zone runs down the eastern side of North America. In winter, when standard time applies, these places are on EST:

A large share of the US population lives in the Eastern zone, which is part of why EST is the default reference for American TV schedules, market hours and conference calls.

What is the difference between EST and EDT?

EST is the winter offset, UTC-5. EDT is Eastern Daylight Time, UTC-4, used in summer. The East Coast switches between the two when daylight saving starts and ends, so the clock moves forward an hour in spring and back an hour in autumn. For most of the year the East Coast is actually on EDT, not EST.

For a fuller breakdown of when each applies, see EST vs EDT.

EST vs ET: which should I say?

"ET" means Eastern Time, the general name for the zone. It refers to whichever offset is current: EST in winter, EDT in summer. So "ET" is always correct, while "EST" is only correct in the winter months. When you are not certain which is in effect, write ET.

What does EST mean for scheduling?

If you book a call with someone "at 3 PM EST" in June, you may be an hour out, because that person is really on EDT. The reliable habit is to read each person's actual local time on the day of the meeting rather than trust the label. That is exactly what Atlas does: it shows everyone's real local clock, daylight saving included, so an "EST" mix-up never costs you a meeting.