IANA tz database · zone identifier

Asia/Kolkata

The IANA tz database identifier for India Standard Time in India. Store this string — not the abbreviation, not the offset — and your timestamps stay correct forever.

UTC+05:30Abbreviation ISTNo daylight saving

Time in Asia/Kolkata☾ Night

04:33:32

Thursday, October 15, 2026

Offset

UTC+05:30

Abbreviation

IST

DST

No DST

Current offset

UTC+05:30

same year-round

Abbreviation

IST

used year-round

DST behaviour

None

one offset all year

Country

🇮🇳 India

ISO 3166: IN · view country page →

Using this identifier

The string to put in your code.

Asia/Kolkata is the identifier to use in code and config for this region. Every modern language, database, and OS resolves it through the same tz database, so the examples here behave identically everywhere.

Avoid storing IST or +05:30 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

// format a date in this zone

new Intl.DateTimeFormat('en-US', {

timeZone: 'Asia/Kolkata',

dateStyle: 'full', timeStyle: 'long'

}).format(new Date());

Offset & DST behaviour

One offset,
80 years.

Asia/Kolkata has kept UTC+05:30 year-round since 14 October 1945 — no daylight saving and no offset changes on record since. It is among the most stable identifiers in the database.

Every offset this zone has kept

Keeping this offset since

14 October 1945

Next transition

None scheduled

no DST rules exist for this zone

Safe to assume

Local = UTC + 5:30h, always

…but store the identifier anyway

Technical record

The database entry, in full.

source: IANA tz database · release 2026d

IdentifierAsia/Kolkata

ISO country codeIN🇮🇳 India

Reference coordinates22.53°N, 88.37°Etz database reference point

Standard offsetUTC+05:30abbreviation IST

Daylight offset—no daylight saving time

tzdb release2026ddata current as of this IANA release

Where it applies

All of India, one clock.

Looking for travel-friendly info? See Delhi or India Standard Time.

🇮🇳

India

1.3B people, one time zone. The whole country resolves to Asia/Kolkata.

Related identifiers

Nearby in the database.

Same zone group · India Standard Time

other identifiers keeping IST

Asia/ColomboSri Lanka

Frequently asked questions

Answers specific to this identifier — generated from the database record. Can't find what you need? Email [email protected].

What UTC offset is Asia/Kolkata?: Asia/Kolkata is UTC+05:30, year-round. The offset never changes because the zone does not observe daylight saving time.
Does Asia/Kolkata observe daylight saving time?: No. Asia/Kolkata stays on UTC+05:30 all year, as it has since 14 October 1945.
Which country uses Asia/Kolkata?: India. The identifier covers the whole country.
Is Asia/Kolkata the same as IST?: Asia/Kolkata is one of the IANA zones that keeps India Standard Time (IST). Use Asia/Kolkata in software — IST is a human-friendly label, not a valid identifier.

Free · Developer API

This zone, as JSON.

Its live offset, abbreviation and DST status, plus its coordinates and country, from one endpoint.

GET /v1/timezones Live

Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.

Get your free API key → All endpoints Plans and pricing

Moving off WorldTimeAPI? Our drop-in replacement needs no key.

// this identifier, resolved live

GET /v1/timezones/Asia/Kolkata

{

"data": {

"iana": "Asia/Kolkata",

"observes_dst": false,

"country": { "code": "IN", "name": "India" },

"current": {

"utc_offset": "+05:30",

"abbreviation": "IST",

…

}