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Time Zone Converter

The time zone converter turns a time in one zone into another, with the offset, the date carry, and whether daylight saving moves the gap during the year.

A wall-clock time in the source zone. 24-hour, so 3pm is 15:00.

In Eastern Standard Time6:00 PM EST

On a 24-hour clock
15:00 PST is 18:00 EST
The offsets
PST is UTC-08:00, EST is UTC-05:00
Difference
EST is 3 hours ahead of PST
Date
Same calendar day.
This gap holds all year
Both zones switch on the same dates, so they move together.
PST is only in force part of the year United States: daylight time starts the second Sunday in March, at 02:00 local time and ends the first Sunday in November, at 02:00 local time (Energy Policy Act of 2005, in force since 2007). In 2026 that is 2026-03-08 to 2026-11-01. Los Angeles is on PDT between those dates.
otherwise PDT, UTC-07:00
Military time zone letters Z (Zulu) is UTC. A to M run east of Greenwich an hour apart, N to Y west, and J is left out. A letter names an offset, so a zone that switches to daylight time changes letter: EST is R, EDT is Q.
PST is U (Uniform), EST is R (Romeo)
In every zone
HST 13:00 AKST 14:00 PST 15:00 AKDT 15:00 MST 16:00 PDT 16:00 CST 17:00 MDT 17:00 EST 18:00 CDT 18:00 EDT 19:00 UTC 23:00 GMT 23:00 BST 00:00 CET 00:00 CEST 01:00 EET 01:00 EEST 02:00 MSK 02:00 IST 04:30 SGT 07:00 HKT 07:00 JST 08:00 AEST 09:00 AEDT 10:00 NZST 11:00 NZDT 12:00

How the Time Zone Converter works

A time zone conversion between abbreviations is one subtraction. EST is UTC-5 and PST is UTC-8 by definition of the abbreviations, so EST is always three hours ahead of PST, and that is exact in the same way an inch is exactly 2.54 centimeters.

What does change is which abbreviation a place is using. New York is on EST from early November to early March and on EDT (UTC-4) for the other eight months. People type "EST" all year. So an invitation reading "3pm EST" in July almost certainly means 3pm in New York, which is EDT, and converting it literally puts you an hour out. That is the most common mistake in time zone conversion.

Some gaps do hold. PST to EST is three hours in January and three in July, because both zones switch on the same dates under the same rule and therefore move together. Others do not. UTC to EST is five hours for about four months and four hours for the other eight, because UTC never shifts and Eastern does.

Daylight saving rules are law rather than definition. In the United States the switch has run from the second Sunday in March to the first Sunday in November since the Energy Policy Act of 2005 took effect in 2007. The European Union and the United Kingdom switch on the last Sunday in March and the last Sunday in October, at 01:00 UTC, so the whole continent changes at the same instant rather than at 02:00 local in each zone. Those dates differ, which creates a three-week window each March when transatlantic meetings are an hour out from their usual slot and nothing is broken.

Three further traps are worth knowing. Abbreviations collide: CST is Central Standard Time at UTC-6, China Standard Time at UTC+8 and Cuba Standard Time at UTC-5, and IST is India, Ireland and Israel. Not everywhere switches: Hawaii, most of Arizona, India, Japan, Russia, Singapore and Hong Kong all hold one offset all year, which means their distance from places that do switch changes twice a year without their clocks moving. And offsets are not all whole hours: India is UTC+05:30.

Time Zone Converter FAQ

What is the difference between UTC and GMT?

UTC is a standard and GMT is a time zone. They share an offset, so the words get used interchangeably, and that is wrong for about seven months of the year: the United Kingdom leaves GMT for British Summer Time from late March to late October, while UTC never shifts for anything. If you mean the reference that aviation, servers and the military use, you mean UTC.

Why is EST sometimes four hours from UTC and sometimes five?

It is not. EST is always UTC-5. What changes is whether the US east coast is on EST at all: from the second Sunday in March to the first Sunday in November it is on EDT, which is UTC-4. If a conversion seems to drift, the abbreviation is the thing that moved, not the offset.

Does this converter know what time it is in New York right now?

No. It converts between abbreviations, whose offsets are definitions, so the arithmetic is exact. Which abbreviation a city is on today depends on the date and its daylight saving rules, and deciding that needs the IANA time zone database and a calendar.

Which time zones do not use daylight saving?

Among the ones here: UTC, Hawaii, India, Japan, Moscow, Singapore and Hong Kong hold a single offset all year, and most of Arizona stays on Mountain Standard Time while the rest of its zone switches. The consequence is counter-intuitive: a zone that never changes still changes its distance from zones that do, twice a year.

Why is India half an hour off?

By choice. India spans nearly two hours of solar time and runs a single zone at UTC+05:30 so that the whole country keeps one clock. Nepal goes further at UTC+05:45. Any system that stores offsets as whole hours cannot represent either.

Two zones have the same offset. Are they the same time?

At that moment, yes. Singapore and Hong Kong are both UTC+8 and their clocks agree exactly, as do Tokyo and Seoul at UTC+9. They are still different zones because they could diverge. A legislature can change its own offset and several have. Converting between them is the rare case with no arithmetic to do.

Common zone conversions

Sources

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