EST vs EDT and other time zone pairs explained, with the tools that get them right

EST and EDT are the two halves of the same US Eastern time zone. Eastern Standard Time is UTC-5 and applies in winter, from the first Sunday in November to the second Sunday in March. Eastern Daylight Time is UTC-4 and applies the rest of the year. As of early November 2026, New York is on EST, and it will switch to EDT on March 14, 2027. Since most people write "EST" all year regardless, the safest habit is to write "ET" or a city name, and to convert with a tool that picks the offset for the meeting date, such as MeetETA's EST time converter.

The same pattern repeats across North America, the UK, Europe and Australia, and a handful of quirks catch people out. This guide covers the common pairs, what they do to the gap with places like India and London, and how to stop thinking about it.

Standard time, daylight time, and why the labels get misused

Every zone that observes daylight saving has two names, one for each season. The Eastern zone covers New York, Washington, Atlanta, Miami and Toronto, and it is EST in winter and EDT in summer. Technically, "3 PM EST" in July describes a time no clock in New York shows, because New York is on EDT then. In practice, almost everyone who writes "EST" in July means "3 PM New York time".

That one hour of ambiguity is behind a lot of missed calls with people overseas. If a colleague in Bangalore reads "3 PM EST" in July and converts it literally as UTC-5, they will arrive an hour late. The neutral labels avoid the problem: ET, CT, MT and PT mean whatever that region is using on the date in question, so they are never wrong.

The common zone pairs side by side

Region	Standard (winter)	Daylight (summer)	Neutral label
US Eastern (New York)	EST, UTC-5	EDT, UTC-4	ET
US Central (Chicago)	CST, UTC-6	CDT, UTC-5	CT
US Mountain (Denver)	MST, UTC-7	MDT, UTC-6	MT
US Pacific (Los Angeles)	PST, UTC-8	PDT, UTC-7	PT
UK (London)	GMT, UTC+0	BST, UTC+1	UK time
Central Europe (Paris, Berlin)	CET, UTC+1	CEST, UTC+2	Central European time
Eastern Australia (Sydney)	AEST, UTC+10	AEDT, UTC+11	Sydney time
India	IST, UTC+5:30	No daylight saving	IST

All four US zones change on the same dates, so the gap between New York and Los Angeles is three hours all year. The UK and EU change together on the last Sundays of March and October. Sydney changes on the first Sunday in October and the first Sunday in April, in the opposite direction to the northern hemisphere.

Three quirks that trip people up

Arizona, outside the Navajo Nation, stays on MST (UTC-7) all year. In winter it matches Denver, and in summer it matches Los Angeles. If you work with someone in Phoenix, "Mountain time" is only half the story.

GMT is not the same as UK time for most of the year. GMT is a fixed UTC+0. From the last Sunday in March to the last Sunday in October, London runs on British Summer Time, UTC+1. A meeting written as "2 PM GMT" in June is, strictly, 3 PM in London.

CST is ambiguous internationally. In the US it means Central Standard Time (UTC-6), but it is also used for China Standard Time (UTC+8). The two are 14 hours apart, so if there is any doubt, add a city.

What EST versus EDT does to the gap with India

India stays on UTC+5:30 all year, so only the American side moves. In winter, when New York is on EST, India is 10 hours 30 minutes ahead. On Tuesday, November 10, 2026, a 9:00 AM call in New York is 7:30 PM in India. In summer, on EDT, the gap is 9 hours 30 minutes, so 9:00 AM in New York on Wednesday, July 15, 2026 was 6:30 PM in India.

Pacific time follows the same rhythm, with India 13 hours 30 minutes ahead of PST in winter and 12 hours 30 minutes ahead of PDT in summer. That shift of one hour is why calls between the US and India tend to drift between "early evening" and "after dinner" in Bangalore over the course of a year.

What it does to the gap with London and Europe

Between New York and London the gap is five hours for most of the year, because both sides change. The exception is the couple of weeks when one side has switched and the other has not. In 2027, New York is only four hours behind London from March 14 to March 27, and again from October 31 to November 6. Central Europe follows the same dates as the UK, so a New York and Paris call drops from six hours to five during those same weeks. Our guide to avoiding daylight saving mistakes goes through those weeks with a worked example.

Letting a converter pick the right offset

Any converter built on the IANA time zone database will get the offset right, as long as you give it a date. MeetETA goes a step further by reading time zone abbreviations the way people actually use them. On meeteta.com/convert you can type "3pm EST to IST" or "11am CST" and get an answer immediately. EST, ET and Eastern are all read as the New York region. If the date falls in summer, MeetETA converts using EDT and adds a note that you probably meant EDT, so you see both the right answer and the reason for it.

When the meeting is not today, add the date: "2026-11-05 09:00 ET" works, and so does "Oct 20 10am PT". GMT is treated as fixed UTC, as it should be. If you mean London's local time, type "London" or "UK" instead, as in "4pm uk time to ist", and MeetETA will apply BST or GMT depending on the date.

For Eastern time in particular, the EST time converter page explains the switch between EST and EDT and converts Eastern time into other zones. If you want to share the converted time, the share button on the converter creates a link that opens in each person's own zone.

Writing times so nobody has to guess

The simplest protection is to stop relying on abbreviations in the first place. "10:00 AM New York time" is never wrong, and neither is "10:00 AM ET". If your calendar shows abbreviations automatically, that is fine, but put the city in the invite description for anyone reading on a phone or forwarding the invite. Add the date for anything that is more than a few days out, and you will rarely have to explain an hour's difference again.