CST and CDT — Central Standard Time and Central Daylight Time
CST (Central Standard Time) means UTC-06:00 and CDT (Central Daylight Time) means UTC-05:00: Chicago keeps CST in winter and CDT in summer.
Current time in CST
09:22:14
Central Standard Time · UTC-06:00
Current time in CDT
10:22:14
Central Daylight Time · UTC-05:00
About CST and CDT
CST is the winter time of the central United States. The same abbreviation is also used for China Standard Time (UTC+8), so always check the context.
Working with CST and CDT
Other labels for the same offsets: MDT for UTC-06:00, and EST for UTC-05:00. One hour to the west of CST in this directory sits MST (UTC-07:00); one hour to the east, EST (UTC-05:00).
The letters CST are also used for China Standard Time (UTC+08:00) and Cuba Standard Time (UTC-05:00). Quote the IANA identifier, America/Chicago, wherever the meaning has to be unambiguous.
Clock changes in CST and CDT
Chicago follows the North American rule: clocks go forward on the second Sunday in March and back on the first Sunday in November, at 02:00 local time.
| Date | Change | New offset |
|---|---|---|
| March 14, 2027 | Clocks go forward one hour on Mar 14, 2027 at 02:00, moving from UTC-06:00 to UTC-05:00. | UTC-05:00 |
| November 7, 2027 | Clocks go back one hour on Nov 7, 2027 at 02:00, moving from UTC-05:00 to UTC-06:00. | UTC-06:00 |
Clock history of America/Chicago
| Period | Clocks set to | Seasonal changes |
|---|---|---|
| since 1945 | UTC-06:00 | 81 years with a change, 1946–2026 |
| 1942–1945 | UTC-05:00 | none |
| 1900–1942 | UTC-06:00 | 24 years with a change, 1918–1941 |
Who keeps UTC-06:00 and UTC-05:00
Moving between UTC-06:00 and UTC-05:00 through the year: Chicago, Houston and Dallas.
Countries and territories whose clocks move between UTC-06:00 and UTC-05:00: parts of Canada, parts of Chile, parts of Mexico and parts of the United States.
UTC-06:00
All year: Mexico City and Calgary. Part of the year: Denver from March 14, 2027 to November 7, 2027.
Countries and territories that keep UTC-06:00 all year, from every entry in the tz database: Belize, parts of Canada, Costa Rica, parts of Ecuador, El Salvador, Guatemala, Honduras, parts of Mexico and Nicaragua. Also on UTC-06:00 for part of the year: parts of Canada, parts of Mexico and parts of the United States. Where it is kept all year, UTC-06:00 also goes by these names in the tz database: Galapagos Time and Mountain Daylight Time.
UTC-05:00
All year: Lima, Bogotá and Panama City. Part of the year: New York, Toronto, Havana, Montreal, Washington, D.C., Boston, Atlanta and Miami until March 14, 2027 and from November 7, 2027.
Countries and territories that keep UTC-05:00 all year, from every entry in the tz database: parts of Brazil, parts of Canada, Cayman Islands, Colombia, parts of Ecuador, Jamaica, parts of Mexico, Panama and Peru. Also on UTC-05:00 for part of the year: the Bahamas, parts of Canada, Cuba, Haiti, Turks & Caicos Islands and parts of the United States. Where it is kept all year, UTC-05:00 also goes by these names in the tz database: Acre Standard Time, Colombia Standard Time, Eastern Standard Time, Ecuador Time and Peru Standard Time.
| City | Longitude | Solar noon on CST / CDT |
|---|---|---|
| Lima | 77.04°W | 11:08 / 12:08 |
| Mexico City | 99.13°W | 12:37 / 13:37 |
| New York | 74.01°W | 10:56 / 11:56 |
| Bogotá | 74.07°W | 10:56 / 11:56 |
| Toronto | 79.38°W | 11:18 / 12:18 |
| Chicago | 87.63°W | 11:51 / 12:51 |
| Houston | 95.37°W | 12:21 / 13:21 |
| Havana | 82.37°W | 11:29 / 12:29 |
| Montreal | 73.57°W | 10:54 / 11:54 |
| Calgary | 114.07°W | 13:36 / 14:36 |
Which of CST and CDT applies today
America/Chicago is on CST (UTC-06:00) at the moment. On March 14, 2027, 132 days from the day this page was generated, its clocks move to CDT (UTC-05:00).
A working day on CST and CDT
| Place | CST’s 09:00–17:00 there | CDT’s 09:00–17:00 there | Shared on CST, over the next 12 months | Shared on CDT, over the next 12 months |
|---|---|---|---|---|
| UTC | 15:00–23:00 | 14:00–22:00 | — | — |
| New York | 10:00–18:00 / 11:00–19:00 | 09:00–17:00 / 10:00–18:00 | 6 h to 7 h | 7 h to 8 h |
| London | 15:00–23:00 / 16:00–00:00 | 14:00–22:00 / 15:00–23:00 | 1 h to 2 h | 2 h to 3 h |
| Tokyo | 00:00–08:00 (next day) | 23:00–07:00 | none all year | none all year |
At 09:00 on a Monday on CST time, every city in this directory has already reached Monday. By 17:00 on a Friday on CST time, New Delhi, Shanghai, Beijing, Mumbai, Shenzhen, Karachi and 72 more have already reached Saturday. For part of the year, so have London, Dublin, Manchester, Lisbon and Edinburgh.
For the working hours Chicago shares with New York, London and Tokyo, and for its sunrise and sunset through the year, see the Chicago page.
How CST and CDT compare with other zones
Right now CST runs ahead of Los Angeles and behind UTC, New York, London, Berlin, Dubai, Kolkata, Singapore, Tokyo and Sydney.
| Zone | UTC offset | Difference from CST | Difference from CDT | Against CST, over the next 12 months |
|---|---|---|---|---|
| UTC | UTC+00:00 | 6h behind | 5h behind | all year |
| New York | UTC-05:00 | 1h behind | Same time | 1h behind / 2h behind |
| London | UTC+00:00 | 6h behind | 5h behind | 6h behind / 7h behind |
| Berlin | UTC+01:00 | 7h behind | 6h behind | 7h behind / 8h behind |
| Dubai | UTC+04:00 | 10h behind | 9h behind | all year |
| Kolkata | UTC+05:30 | 11h 30m behind | 10h 30m behind | all year |
| Singapore | UTC+08:00 | 14h behind | 13h behind | all year |
| Tokyo | UTC+09:00 | 15h behind | 14h behind | all year |
| Sydney | UTC+11:00 | 17h behind | 16h behind | 16h behind / 17h behind |
| Los Angeles | UTC-08:00 | 2h ahead | 3h ahead | 2h ahead / 1h ahead |
Cities using CST and CDT
CST
CDT
Convert CST and CDT to another zone
Related time zones
Time zone rules: IANA tz database release 2026c, applied when this page was generated on 2026-11-02.
Frequently asked questions
What are CST and CDT?
CST is Central Standard Time, UTC-06:00, and CDT is Central Daylight Time, UTC-05:00. CDT is the daylight saving time of the central United States.
What is the IANA identifier for CST and CDT?
America/Chicago, named after Chicago. It has moved between UTC-06:00 and UTC-05:00 on the same yearly pattern since 2007.
When is it CST and when is it CDT in Chicago?
Over the coming year Chicago is on CDT (UTC-05:00) from March 14, 2027 to November 7, 2027, and on CST (UTC-06:00) until March 14, 2027 and from November 7, 2027. The labels themselves never move: CST always means UTC-06:00 and CDT always means UTC-05:00. Mexico City keeps CST all year.
What time is it on CST and CDT when it is 09:00 in London?
On CST: 03:00 until March 28, 2027 and from October 31, 2027; 02:00 from March 28, 2027 to October 31, 2027. On CDT: 04:00 until March 28, 2027 and from October 31, 2027; 03:00 from March 28, 2027 to October 31, 2027.
Is CST the same as MDT?
As labels, both mean UTC-06:00. The places behind them, Chicago and Denver, do not keep the same clock for a whole day at any point in the coming year.
Is CDT the same as EST?
As labels, both mean UTC-05:00. The places behind them, Chicago and New York, do not keep the same clock for a whole day at any point in the coming year.