CHST: Chamorro Standard Time
CHST is Chamorro Standard Time, +10:00, used in Oceania. In code, use Pacific/Guam rather than the abbreviation.
Chamorro Standard Time · Oceania
11:45:49
Sunday, 27 September 2026
- abbreviation denotes
- +10:00
- in force right now
- ChST (UTC+10:00)
- use in code
- Pacific/Guam
- next clock change
- none, fixed offset
Right now this zone is on ChST, not CHST. 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("Pacific/Guam"))
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'tCHST questions
What does CHST stand for?
CHST is Chamorro Standard Time, +10:00, used in Oceania. The IANA zone to use in code is Pacific/Guam.
What time is it in CHST right now?
Chamorro Standard Time: 11:45 on Sunday (ChST).
Which IANA timezone should I use instead of CHST?
Pacific/Guam for Chamorro 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 ChST instead of CHST?
Because Pacific/Guam is currently on ChST (UTC+10:00), its daylight-saving variant. CHST (+10:00) applies during the other half of the year. Both names refer to the same place, one hour apart.