CST — which one do you mean?
CST means 3 different things, and they are
hours apart. If you received a timestamp labelled CST, the sender's
location decides which of these applies — pick it below.
Central Standard Time · North America
19:26:04
Wednesday, 12 August 2026
- abbreviation denotes
- -06:00
- in force right now
- CDT (UTC-05:00) · DST
- use in code
- America/Chicago
- also valid
- America/Winnipeg, America/Mexico_City
- next clock change
- 1 Nov 2026 01:00 → CST
US and Canadian midwest, winter half of the year.
Right now this zone is on CDT, not CST —
they are the same place at different times of year.
China Standard Time · Asia
08:26:04
Thursday, 13 August 2026
- abbreviation denotes
- +08:00
- in force right now
- CST (UTC+08:00)
- use in code
- Asia/Shanghai
- also valid
- Asia/Macau
- next clock change
- none — fixed offset
All of mainland China runs on this single zone.
Cuba Standard Time · Caribbean
20:26:04
Wednesday, 12 August 2026
- abbreviation denotes
- -05:00
- in force right now
- CDT (UTC-04:00) · DST
- use in code
- America/Havana
- next clock change
- 1 Nov 2026 00:00 → CST
Cuba observes daylight saving as CDT (UTC-4).
Right now this zone is on CDT, not CST —
they are the same place at different times of year.
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'tCST questions
What does CST stand for?
CST has 3 distinct meanings in active use: Central Standard Time (-06:00, America/Chicago); China Standard Time (+08:00, Asia/Shanghai); Cuba Standard Time (-05:00, America/Havana). Which one applies depends entirely on who wrote the timestamp.
What time is it in CST right now?
Central Standard Time: 19:26 on Wednesday (CDT); China Standard Time: 08:26 on Thursday (CST); Cuba Standard Time: 20:26 on Wednesday (CDT).
Which IANA timezone should I use instead of CST?
America/Chicago for Central Standard Time, Asia/Shanghai for China Standard Time, America/Havana for Cuba Standard 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.
Why does my computer show CDT instead of CST?
Because America/Chicago is currently on CDT (UTC-05:00), its daylight-saving variant. CST (-06:00) applies during the other half of the year. Both names refer to the same place, one hour apart.