CDT can mean 2 different things depending on where you are: Central Daylight Time (UTC-5); Cuba Daylight Time (UTC-4). Each is explained below.
CDT stands for Central Daylight Time and is UTC-5, which is 5 hours behind UTC.
CDT is used only while daylight saving time is in effect. When it ends, the same places return to CST (UTC-6).
Cities that use CDT: Chicago, Houston, Dallas, Austin, Nashville, Memphis, Milwaukee, Kansas City, Oklahoma City, New Orleans, St. Louis, Omaha, Birmingham, US, Little Rock and 11 more.
| When it is… | 9:00 AM CDT | 12:00 PM CDT | 5:00 PM CDT |
|---|---|---|---|
| UTC | 2:00 PM | 5:00 PM | 10:00 PM |
| PST (Pacific) | 6:00 AM | 9:00 AM | 2:00 PM |
| MST (Mountain) | 7:00 AM | 10:00 AM | 3:00 PM |
| CST (Central US) | 8:00 AM | 11:00 AM | 4:00 PM |
| CET (Central Europe) | 3:00 PM | 6:00 PM | 11:00 PM |
| EET (Eastern Europe) | 4:00 PM | 7:00 PM | 12:00 AM (+1 day) |
| IST (India) | 7:30 PM | 10:30 PM | 3:30 AM (+1 day) |
| JST (Japan) | 11:00 PM | 2:00 AM (+1 day) | 7:00 AM (+1 day) |
| AEST (Sydney) | 12:00 AM (+1 day) | 3:00 AM (+1 day) | 8:00 AM (+1 day) |
CDT stands for Cuba Daylight Time and is UTC-4, which is 4 hours behind UTC.
CDT is used only while daylight saving time is in effect. When it ends, the same places return to CST (UTC-5).
Cities that use CDT: Havana, Varadero.
| When it is… | 9:00 AM CDT | 12:00 PM CDT | 5:00 PM CDT |
|---|---|---|---|
| UTC | 1:00 PM | 4:00 PM | 9:00 PM |
| PST (Pacific) | 5:00 AM | 8:00 AM | 1:00 PM |
| MST (Mountain) | 6:00 AM | 9:00 AM | 2:00 PM |
| CST (Central US) | 7:00 AM | 10:00 AM | 3:00 PM |
| EST (Eastern) | 8:00 AM | 11:00 AM | 4:00 PM |
| CET (Central Europe) | 2:00 PM | 5:00 PM | 10:00 PM |
| EET (Eastern Europe) | 3:00 PM | 6:00 PM | 11:00 PM |
| IST (India) | 6:30 PM | 9:30 PM | 2:30 AM (+1 day) |
| JST (Japan) | 10:00 PM | 1:00 AM (+1 day) | 6:00 AM (+1 day) |
| AEST (Sydney) | 11:00 PM | 2:00 AM (+1 day) | 7:00 AM (+1 day) |
CDT can stand for Central Daylight Time; Cuba Daylight Time.
Central Daylight Time is UTC-5. Cuba Daylight Time is UTC-4.
CDT is UTC-5 and CST is UTC-6, a difference of 1 hour. Places that use both switch between them when daylight saving time starts and ends. The live line above shows which one applies right now.
It depends on context. Look at the place or the schedule the abbreviation comes from, or ask for the UTC offset to be written out, such as UTC+8 instead of CST.