IANA tz database · zone identifier

America/Denver

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

UTC-06:00Abbreviation MDTObserves daylight saving
Time in America/Denver☀ Daylight
16:57:12
Wednesday, July 15, 2026
Offset
UTC-06:00
Abbreviation
MDT
DST
Active

Current offset

UTC-06:00

standard UTC-07:00 · daylight UTC-06:00

Abbreviation

MDT

the daylight-saving form

DST behaviour

Observes

changes clocks twice a year

Country

🇺🇸 United States

ISO 3166: US · view country page →

Using this identifier

The string to put in your code.

America/Denver 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 MDT or -06:00 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

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

Offset & DST behaviour

Two offsets,
every year.

America/Denver alternates between MST (UTC-07:00) and MDT (UTC-06:00). Right now it is on MDT; clocks fall back on 1 November 2026.

The year at a glance

MST · UTC-07:00MDT · UTC-06:00MST · UTC-07:008 Mar · +1h1 Nov · −1h Jan 2026 Dec

Technical record

The database entry, in full.

source: IANA tz database

IdentifierAmerica/Denver
ISO country codeUS🇺🇸 United States
Reference coordinates39.74°N, 104.98°Wtz database reference point
Standard offsetUTC-07:00abbreviation MST
Daylight offsetUTC-06:00abbreviation MDT

Where it applies

One of United States's 29 zones.

Looking for travel-friendly info? See Denver or Mountain Standard Time.

🇺🇸
United States

340M people, 29 time zones — this identifier covers one of them.

Country page →
🇺🇸 Denver
16:57
16:57:12 · MDT
pop. 716KMST
🇺🇸 El Paso
16:57
16:57:12 · MDT
pop. 679KMST
🇺🇸 Albuquerque
16:57
16:57:12 · MDT
pop. 565KMST

Related identifiers

Nearby in the database.

Same zone group · Mountain Standard Time

other identifiers keeping MST

Same offset · UTC-06:00

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/Denver?
America/Denver is currently UTC-06:00 (MDT). It alternates between UTC-07:00 in winter and UTC-06:00 in summer.
Does America/Denver observe daylight saving time?
Yes. Clocks fall back at the next transition on 1 November 2026, as they do twice every year.
Which country uses America/Denver?
United States. It is one of 29 IANA zones covering the country.
Is America/Denver the same as MST?
America/Denver is one of the IANA zones that keeps Mountain Standard Time (MST). Use America/Denver in software — MST 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/Denver
{
"iana": "America/Denver",
"utc_offset": "-06:00",
"abbreviation": "MDT",
"observes_dst": true,
"country": "US"
}