IANA tz database · zone identifier

Asia/Seoul

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

UTC+09:00Abbreviation KSTNo DST — never observed

Time in Asia/Seoul☀ Daylight

07:58:30

Thursday, July 16, 2026

Offset

UTC+09:00

Abbreviation

KST

DST

No DST

Current offset

UTC+09:00

same year-round

Abbreviation

KST

used year-round

DST behaviour

Never

has never observed daylight saving

Country

🇰🇷 South Korea

ISO 3166: KR · view country page →

Using this identifier

The string to put in your code.

Asia/Seoul 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 KST or +09:00 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

// format a date in this zone

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

timeZone: 'Asia/Seoul',

dateStyle: 'full', timeStyle: 'long'

}).format(new Date());

Offset & DST behaviour

One offset,
37 years.

Asia/Seoul has kept UTC+09:00 year-round since 9 October 1988 — 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

9 October 1988

Next transition

None scheduled

no DST rules exist for this zone

Safe to assume

Local = UTC + 9h, always

…but store the identifier anyway

Technical record

The database entry, in full.

source: IANA tz database

IdentifierAsia/Seoul

ISO country codeKR🇰🇷 South Korea

Reference coordinates37.55°N, 126.97°Etz database reference point

Standard offsetUTC+09:00abbreviation KST

Daylight offset—daylight saving has never been observed

Where it applies

All of South Korea, one clock.

Looking for travel-friendly info? See Seoul or Korean Standard Time.

🇰🇷

South Korea

51M people, one time zone. The whole country resolves to Asia/Seoul.

Related identifiers

Nearby in the database.

Same zone group · Korean Standard Time

other identifiers keeping KST

Asia/PyongyangNorth Korea

Same offset · UTC+09:00

other zones keeping this offset right now

Asia/ChitaRussia · Yakutsk Standard Time Asia/DiliTimor-Leste · East Timor Time Asia/KhandygaRussia · Yakutsk Standard Time Asia/TokyoJapan · Japan Standard Time Asia/YakutskRussia · Yakutsk Standard Time Pacific/PalauPalau · Palau Time

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/Seoul?: Asia/Seoul is UTC+09:00, year-round. The offset never changes because the zone does not observe daylight saving time.
Does Asia/Seoul observe daylight saving time?: No. Asia/Seoul has never observed DST — it has kept UTC+09:00 continuously since 9 October 1988.
Which country uses Asia/Seoul?: South Korea. The identifier covers the whole country.
Is Asia/Seoul the same as KST?: Asia/Seoul is one of the IANA zones that keeps Korean Standard Time (KST). Use Asia/Seoul in software — KST is a human-friendly label, not a valid identifier.

Free · Developer API

This zone, as JSON.

Everything on this page — offset, abbreviation, DST rules, coordinates — from one endpoint, always current with the latest tzdb release.

GET /v1/timezones Live

countries, cities, convert, DST transitions coming next.

Get your free API key →

// this identifier, resolved live

GET /v1/timezones?iana=Asia/Seoul

{

"iana": "Asia/Seoul",

"utc_offset": "+09:00",

"abbreviation": "KST",

"observes_dst": false,

"country": "KR"

}