IANA tz database · zone identifier

America/Chicago

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

UTC-05:00Abbreviation CDTObserves daylight saving
Time in America/Chicago☀ Daylight
17:58:03
Wednesday, July 15, 2026
Offset
UTC-05:00
Abbreviation
CDT
DST
Active

Current offset

UTC-05:00

standard UTC-06:00 · daylight UTC-05:00

Abbreviation

CDT

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/Chicago 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 CDT or -05:00 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

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

Offset & DST behaviour

Two offsets,
every year.

America/Chicago alternates between CST (UTC-06:00) and CDT (UTC-05:00). Right now it is on CDT; clocks fall back on 1 November 2026.

The year at a glance

CST · UTC-06:00CDT · UTC-05:00CST · UTC-06:008 Mar · +1h1 Nov · −1h Jan 2026 Dec

Technical record

The database entry, in full.

source: IANA tz database

IdentifierAmerica/Chicago
ISO country codeUS🇺🇸 United States
Reference coordinates41.85°N, 87.65°Wtz database reference point
Standard offsetUTC-06:00abbreviation CST
Daylight offsetUTC-05:00abbreviation CDT

Where it applies

One of United States's 29 zones.

Looking for travel-friendly info? See Chicago or Central Standard Time.

🇺🇸
United States

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

Country page →
🇺🇸 Chicago
17:58
17:58:03 · CDT
pop. 2.7MCST
🇺🇸 Houston
17:58
17:58:03 · CDT
pop. 2.3MCST
🇺🇸 San Antonio
17:58
17:58:03 · CDT
pop. 1.4MCST

Related identifiers

Nearby in the database.

Same zone group · Central Standard Time

other identifiers keeping CST

Same offset · UTC-05:00

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/Chicago?
America/Chicago is currently UTC-05:00 (CDT). It alternates between UTC-06:00 in winter and UTC-05:00 in summer.
Does America/Chicago 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/Chicago?
United States. It is one of 29 IANA zones covering the country.
Is America/Chicago the same as CST?
America/Chicago is one of the IANA zones that keeps Central Standard Time (CST). Use America/Chicago in software — CST 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/Chicago
{
"iana": "America/Chicago",
"utc_offset": "-05:00",
"abbreviation": "CDT",
"observes_dst": true,
"country": "US"
}