Timezone Abbreviation Lookup

Search timezone abbreviations (EST, PST, IST, etc.) to find UTC offset, full name, and current time.

Tested tool guide Tested browser tools Checked August 16, 2026

What Timezone Abbreviation Lookup does, with a checked example

An abbreviation like EST or JST on an invite, a flight board, or a log file - this page turns it into the full zone name, the UTC offset, and the current time there, computed from the device clock with nothing sent to a server. The common mistake is trusting the letters: an abbreviation is a label, not a rule. CST is Central Standard Time (UTC-6) or China Standard Time (UTC+8), and IST is India (UTC+5:30) or Ireland (UTC+1). Standard-time codes also sleep for months each year: in August no US clock reads EST - the Eastern zone runs on EDT (UTC-4).

Worked example

A concrete input and expected output from the current implementation.

Input

JST

Expected output

Japan Standard Time - UTC+9 - no daylight saving - current time 21:00 when the device clock reads 12:00 UTC

JST is the standard abbreviation for Japan Standard Time, and Japan does not observe daylight saving, so the UTC+9 offset holds every month of the year. Applying the offset to any UTC reading gives the JST clock: 12:00 UTC plus 9 hours is 21:00.

How the result is produced

The lookup table

The tool looks up abbreviations against a fixed list, each code mapped to one full zone name and one fixed offset: EST to Eastern Standard Time at UTC-5, PDT to Pacific Daylight Time at UTC-7, GMT and UTC to UTC+0. Typing in the search box filters the list, and each matching row carries the name, the offset, and a current-time line that applies the offset to the device clock.

One code, one offset

Every code maps to exactly one offset, and the tool never decides which season you mean. EST is always UTC-5 and EDT is always UTC-4, listed as separate codes. The result is a definition, not a forecast: the offset row describes the abbreviation, while the current-time line follows the device clock. Zones without daylight saving, such as Japan's JST, hold one offset all year.

Good uses

Decode an abbreviation in a meeting invite - '9 AM EST' - into its full name and UTC offset so you can translate it to your own zone before dialing in.
Check a flight arrival or departure listed in local time with an abbreviation you do not recognize, such as AEST for Sydney (UTC+10), to see what that means in your own timezone while booking the connection.
Before sending an international invitation or writing documentation that labels a time, verify the abbreviation you plan to use has only the meaning you intend - for example, that CST will not be read as China Standard Time (UTC+8) by the recipients.

Limits and checks

Shared codes: CST is Central Standard Time (UTC-6) or China Standard Time (UTC+8), and IST is India (UTC+5:30) or Ireland (UTC+1, summer only). An abbreviation without the offset or the country is ambiguous, so confirm which zone the other party means before relying on it.
Season mismatch: EST, CST, and PST are standard-time codes. From mid-March to early November the US Eastern zone runs on EDT (UTC-4), so an EST lookup in summer returns the winter definition and a time no local clock shows. Match the code to the season, or use the zone name, before trusting it.
Offset is not identity: UTC+9 is shared by Japan and South Korea, and UTC-5 by the US Eastern zone in winter, Colombia, and Peru. Zones sharing an offset can change clocks on different dates, so for anything scheduled, name the full zone such as America/New_York rather than the abbreviation.

Common questions

Why does EST still show UTC-5 in August, when it is summer?

Because EST is the standard-time code and US standard time is not running in August. The Eastern zone is on EDT (UTC-4) from the second Sunday in March to the first Sunday in November. The page reports what the abbreviation is defined to mean - UTC-5 - since it cannot know whether the writer of 'EST' meant the summer code. Use EDT during daylight-saving months.

Which IST is it - India or Ireland?

Both exist, which is why the code alone is not enough. India Standard Time is fixed at UTC+5:30 all year; Irish Standard Time is UTC+1 in summer, and Ireland falls back to GMT (UTC+0) in winter. The offset decides: a UTC+5:30 'IST' is India, while a UTC+1 'IST' in July is Ireland. For anything scheduled, use the IANA zone name instead - Asia/Kolkata or Europe/Dublin.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.