Twenty-five IANA zones fall under the Central Time metazone. They do not all behave the same way. Some spring forward and fall back. Others stay fixed at UTC−6 all year. The split runs right through Mexico.
Live Clocks for Every Central Time IANA Zone
| IANA Zone | Current Offset | DST? |
|---|---|---|
| America/Chicago | UTC−5 (CDT) | Yes |
| America/Mexico_City | UTC−6 (CST) | No |
| America/Winnipeg | UTC−5 (CDT) | Yes |
| America/Regina | UTC−6 (CST) | No |
Which US Zones Use Central Time?
Eleven US IANA zones sit in the Central Time group. All observe DST.
| IANA Zone | Representative City | Current Offset |
|---|---|---|
| America/Chicago | Chicago, IL | UTC−5 (CDT) |
| America/Indiana/Knox | Knox, IN | UTC−5 (CDT) |
| America/Indiana/Tell_City | Tell City, IN | UTC−5 (CDT) |
| America/Menominee | Menominee, WI | UTC−5 (CDT) |
| America/North_Dakota/Beulah | Beulah, ND | UTC−5 (CDT) |
| America/North_Dakota/Center | Center, ND | UTC−5 (CDT) |
| America/North_Dakota/New_Salem | New Salem, ND | UTC−5 (CDT) |
Chicago has 2,664,452 residents. Dallas, Houston, and San Antonio also run on America/Chicago time. Dallas clocks 1,326,087 people. Houston has 2,314,157. San Antonio counts 1,526,656.
Mexico Central Zones: Mexico City, Monterrey, and the Border Split
Mexico abolished DST nationally in October 2022. The change took effect in 2023. Northern border municipalities kept US DST for economic reasons. The result: Mexico City stays on UTC−6 while Chicago springs forward to UTC−5 in summer.
| IANA Zone | Representative City | Current Offset | DST? |
|---|---|---|---|
| America/Mexico_City | Mexico City | UTC−6 (CST) | No |
| America/Monterrey | Monterrey | UTC−6 (CST) | No |
| America/Merida | Mérida | UTC−6 (CST) | No |
| America/Chihuahua | Chihuahua | UTC−6 (CST) | No |
| America/Bahia_Banderas | Bahía de Banderas | UTC−6 (CST) | No |
| America/Matamoros | Matamoros | UTC−5 (CDT) | Yes |
| America/Ojinaga | Ojinaga | UTC−5 (CDT) | Yes |
Mexico City is the national capital. Population: 12,294,193. On the June solstice, sunrise hits at 05:58 and sunset at 19:16. That is 13 hours 18 minutes of daylight. On the December solstice, the city gets 10 hours 57 minutes: sunrise at 07:05, sunset at 18:03.
Monterrey holds 1,135,512 people. Mérida: 1,201,000. Matamoros and Ojinaga follow the US DST schedule. They are on the same clock as Chicago year-round.
Canada Central Zones: Winnipeg, Regina, Rankin Inlet
Canada splits the same way. Manitoba and parts of Nunavut observe DST. Saskatchewan does not.
| IANA Zone | Representative City | Current Offset | DST? |
|---|---|---|---|
| America/Winnipeg | Winnipeg, MB | UTC−5 (CDT) | Yes |
| America/Rankin_Inlet | Rankin Inlet, NU | UTC−5 (CDT) | Yes |
| America/Resolute | Resolute, NU | UTC−5 (CDT) | Yes |
| America/Regina | Regina, SK | UTC−6 (CST) | No |
| America/Swift_Current | Swift Current, SK | UTC−6 (CST) | No |
Regina and Swift Current sit on CST year-round. In winter, Regina matches Chicago. In summer, Regina is one hour behind.
Central America Zones: Year-Round CST
Six zones in Central America stay on UTC−6 permanently. No DST, ever.
| IANA Zone | Representative City | Current Offset |
|---|---|---|
| America/Belize | Belmopan | UTC−6 |
| America/Costa_Rica | San José | UTC−6 |
| America/El_Salvador | San Salvador | UTC−6 |
| America/Guatemala | Guatemala City | UTC−6 |
| America/Managua | Managua | UTC−6 |
| America/Tegucigalpa | Tegucigalpa | UTC−6 |
When Do Central Time Clocks Change?
US and Canadian zones that observe DST follow the same schedule. Clocks go forward on the second Sunday in March at 02:00 local. They fall back on the first Sunday in November at 02:00 local.
In 2026: Sunday 8 March, clocks jump from 02:00 to 03:00. CST becomes CDT. Sunday 1 November, clocks drop from 02:00 to 01:00. CDT becomes CST.
In 2027: Sunday 14 March, forward one hour. Sunday 7 November, back one hour.
Mexico City, Regina, and all six Central American zones ignore these dates. Their clocks do not move.
What Is the Time Difference to Other Cities?
On 15 January 2026, when the reference zone is on CST:
- New York: 1 hour ahead
- Los Angeles: 2 hours behind
- London: 6 hours ahead
- Paris: 7 hours ahead
- Dubai: 10 hours ahead
- Mumbai: 11.5 hours ahead
- Singapore: 14 hours ahead
- Tokyo: 15 hours ahead
- Sydney: 17 hours ahead
- Johannesburg: 8 hours ahead
- São Paulo: 3 hours ahead
On 15 July 2026, when the reference zone is on CDT:
- New York: 1 hour ahead
- Los Angeles: 2 hours behind
- London: 6 hours ahead
- Paris: 7 hours ahead
- Dubai: 9 hours ahead
- Mumbai: 10.5 hours ahead
- Singapore: 13 hours ahead
- Tokyo: 14 hours ahead
- Sydney: 15 hours ahead
- Johannesburg: 7 hours ahead
- São Paulo: 2 hours ahead
Why Does CST Mean Three Different Things?
CST is ambiguous. It stands for Central Standard Time (North America, UTC−6). It also stands for China Standard Time (UTC+8) and Cuba Standard Time (UTC−5). In international contexts, write "America/Chicago" or "UTC−6" to avoid confusion.
CDT carries the same problem. It means Central Daylight Time in North America. It can also mean Cuba Daylight Time.
"Central Time" (CT) is the safe umbrella. It covers both CST and CDT without specifying which is active. Many people say "CST" year-round out of habit. A meeting invite for "6 p.m. CST" in July is technically wrong. It should say CDT. Most people understand anyway.
Does All of Mexico Observe DST?
No. The assumption that Mexico follows the US DST schedule died in 2022. Most of the country abolished DST effective 2023. Mexico City is on permanent CST. It matches Chicago from November to March. It sits one hour behind from March to November.
Border municipalities within roughly 20 km of the US border can keep US DST. Matamoros and Ojinaga do. Check the local time zone law for specific cities. The relevant Mexican legislation is the Ley del Sistema Horario.
Is Saskatchewan on Central Time?
Yes, but with a twist. Saskatchewan is geographically in the Mountain Time zone. It legally observes CST year-round. That means no DST. Regina matches Chicago in winter. In summer, Regina is one hour behind. The IANA zones are America/Regina and America/Swift_Current.