BST: which one do you mean?
BST means 2 different things, and they are hours apart. If you received a timestamp labelled BST, the sender's location decides which of these applies, so pick it below.
British Summer Time · Europe
23:00:44
Saturday, 14 November 2026
- abbreviation denotes
- +01:00
- in force right now
- GMT (UTC+00:00)
- use in code
- Europe/London
- next clock change
- 28 Mar 2027 02:00 → BST
Right now this zone is on GMT, not BST. They are the same place at different times of year.
Bangladesh Standard Time · Asia
05:00:44
Sunday, 15 November 2026
- abbreviation denotes
- +06:00
- in force right now
- UTC+06:00 (UTC+06:00)
- use in code
- Asia/Dhaka
- next clock change
- none, fixed offset
Right now this zone is on UTC+06:00, not BST. 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("Europe/London"))
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'tBST questions
What does BST stand for?
BST has 2 distinct meanings in active use: British Summer Time (+01:00, Europe/London); Bangladesh Standard Time (+06:00, Asia/Dhaka). Which one applies depends entirely on who wrote the timestamp.
What time is it in BST right now?
British Summer Time: 23:00 on Saturday (GMT); Bangladesh Standard Time: 05:00 on Sunday (UTC+06:00).
Which IANA timezone should I use instead of BST?
Europe/London for British Summer Time, Asia/Dhaka for Bangladesh 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 GMT instead of BST?
Because Europe/London is currently on GMT (UTC+00:00), its daylight-saving variant. BST (+01:00) applies during the other half of the year. Both names refer to the same place, one hour apart.