CDT — Central Daylight Time
Daylight variant of North American CST — UTC-5.
CDT stands for Central Daylight Time. Daylight variant of North American CST — UTC-5.
CDT is UTC-05:00 from Coordinated Universal Time (UTC). The primary IANA zone is America/Chicago.
CDT is a daylight-saving time abbreviation. It is used when clocks are advanced from CST (UTC-06:00) during summer months.
Standard / daylight pair
CST · UTC−6 — November–March in North America
Where this abbreviation is used
| Meaning | Offset | Region |
|---|---|---|
| Central Daylight Time (North America) | UTC−5 | Central United States, Central Canada, and Mexican border municipalities. |
| Cuba Daylight Time | UTC−4 | Republic of Cuba. |
Countries using this zone
- United States
- Canada
- Mexico
- Cuba
Principal cities
- Chicago
- Houston
- Dallas
- Winnipeg
- Havana
- San Antonio
- Oklahoma City
- Matamoros
History
In the United States and Canada, the current Daylight Saving Time schedule was mandated by the Energy Policy Act of 2005, which extended the period of daylight time to improve energy efficiency. Most of Mexico abolished the observation of daylight saving time in October 2022, though 33 border municipalities retained CDT to remain synchronized with neighboring American markets. Cuba typically aligns its transitions with the North American schedule but retains a distinct UTC offset for its summer period.
Frequently Asked Questions
CDT — Central Daylight Time. Daylight variant of North American CST — UTC-5.
CDT is UTC-05:00. It is paired with CST (UTC-06:00).
Countries and territories primarily using CDT include: US, CA, MX.
CDT IS the daylight-saving variant. Zones shift from CST to CDT at the start of summer and back to CST at the end.
CDT is the summer (daylight-saving) abbreviation and CST is the winter (standard) abbreviation. CDT is one hour ahead of CST.
The primary IANA time zone representing CDT is America/Chicago. Operating systems and programming libraries use this identifier to resolve local time.
Central Daylight Time (CDT) is a daylight saving time zone used in North America and the Caribbean. It is 5 hours behind Coordinated Universal Time (UTC−5) in the United States and Canada. Clocks are advanced by 1 hour during the summer to take advantage of longer daylight in the evening.
In the United States and Canada, Central Daylight Time begins on the 2nd Sunday of March at 02:00 local time and ends on the 1st Sunday of November at 02:00. During the spring transition, clocks move forward to 03:00, while in the autumn, they are set back to 01:00.
There are 20 states that use CDT in some capacity, including Illinois, Texas, and Minnesota. While most of these states observe it statewide, others like Florida, Indiana, and Kentucky are split between the Central and Eastern time zones. This alignment ensures consistency for regional trade and transportation hubs like Chicago and Houston.
The primary difference between Central Daylight Time (CDT) and Central Standard Time (CST) is the 1-hour offset. CDT is UTC−5, making it 1 hour ahead of the standard UTC−6 offset used during the winter months. Most regions in this zone switch between the two to maximize natural light.
No, Mexico City no longer observes Central Daylight Time. Following a legislative change in October 2022, most of Mexico shifted to permanent Central Standard Time (CST). Only specific municipalities located directly on the United States border continue to observe CDT to maintain synchronicity with American economic centers across the border.