IANA tz database · zone identifier

America/Argentina/San_Luis

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

UTC-03:00Abbreviation -03No DST — never observed
Time in America/Argentina/San_Luis☾ Night
20:01:09
Wednesday, July 15, 2026
Offset
UTC-03:00
Abbreviation
-03
DST
No DST

Current offset

UTC-03:00

same year-round

Abbreviation

-03

tzdb uses numeric abbreviations here

DST behaviour

Never

has never observed daylight saving

Country

🇦🇷 Argentina

ISO 3166: AR · view country page →

Using this identifier

The string to put in your code.

America/Argentina/San_Luis 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 -03 or -03:00 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

// format a date in this zone
new Intl.DateTimeFormat('en-US', {
timeZone: 'America/Argentina/San_Luis',
dateStyle: 'full', timeStyle: 'long'
}).format(new Date());

Offset & DST behaviour

One offset,
16 years.

America/Argentina/San_Luis has kept UTC-03:00 year-round since 11 October 2009 — 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

−04:25:24UTC-03:00 · UNCHANGED 11 October 2009 NOW

Keeping this offset since

11 October 2009

Next transition

None scheduled

no DST rules exist for this zone

Safe to assume

Local = UTC − 3h, always

…but store the identifier anyway

Technical record

The database entry, in full.

source: IANA tz database

IdentifierAmerica/Argentina/San_Luis
ISO country codeAR🇦🇷 Argentina
Reference coordinates33.32°S, 66.35°Wtz database reference point
Standard offsetUTC-03:00abbreviation -03
Daylight offset—daylight saving has never been observed

Where it applies

One of Argentina's 12 zones.

🇦🇷
Argentina

47M people, 12 time zones — this identifier covers one of them.

Country page →

Related identifiers

Nearby in the database.

Same zone group · Argentina Standard Time

other identifiers keeping AST

Same offset · UTC-03:00

other zones keeping this offset right now

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 America/Argentina/San_Luis?
America/Argentina/San_Luis is UTC-03:00, year-round. The offset never changes because the zone does not observe daylight saving time.
Does America/Argentina/San_Luis observe daylight saving time?
No. America/Argentina/San_Luis has never observed DST — it has kept UTC-03:00 continuously since 11 October 2009.
Which country uses America/Argentina/San_Luis?
Argentina. It is one of 12 IANA zones covering the country.
Is America/Argentina/San_Luis the same as AST?
America/Argentina/San_Luis is one of the IANA zones that keeps Argentina Standard Time (AST). Use America/Argentina/San_Luis in software — AST 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=America/Argentina/San_Luis
{
"iana": "America/Argentina/San_Luis",
"utc_offset": "-03:00",
"abbreviation": "-03",
"observes_dst": false,
"country": "AR"
}