Timezone Abbreviation Lookup

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

  • Conversion
  • Runs in your browser
  • Free, no signup

The guide

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

1

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.

2

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.