CDT — which one do you mean?
CDT means 2 different things, and they are
hours apart. If you received a timestamp labelled CDT, the sender's
location decides which of these applies — pick it below.
Central Daylight Time · North America
19:15:46
Wednesday, 12 August 2026
- abbreviation denotes
- -05:00
- in force right now
- CDT (UTC-05:00) · DST
- use in code
- America/Chicago
- next clock change
- 1 Nov 2026 01:00 → CST
Cuba Daylight Time · Caribbean
20:15:46
Wednesday, 12 August 2026
- abbreviation denotes
- -04:00
- in force right now
- CDT (UTC-04:00) · DST
- use in code
- America/Havana
- next clock change
- 1 Nov 2026 00:00 → CST
Use the IANA name, not the abbreviation
Python
from datetime import datetime
from zoneinfo import ZoneInfo
# right: an IANA zone carries the full history of rule changes
now = datetime.now(ZoneInfo("America/Chicago"))
print(now.isoformat(), now.tzname())
# wrong: an abbreviation is not resolvable, and a hard-coded offset
# silently rots the next time the rules change
# now = datetime.now(timezone(timedelta(hours=...))) # don'tCDT questions
What does CDT stand for?
CDT has 2 distinct meanings in active use: Central Daylight Time (-05:00, America/Chicago); Cuba Daylight Time (-04:00, America/Havana). Which one applies depends entirely on who wrote the timestamp.
What time is it in CDT right now?
Central Daylight Time: 19:15 on Wednesday (CDT); Cuba Daylight Time: 20:15 on Wednesday (CDT).
Which IANA timezone should I use instead of CDT?
America/Chicago for Central Daylight Time, America/Havana for Cuba Daylight Time. Date libraries cannot resolve bare abbreviations, and an abbreviation carries no daylight-saving history, so a stored offset silently rots when a government changes the rules.