BST to CHAST Converter
Chatham Island is on daylight saving time: CHADT (UTC+13:45) until Sun, Apr 4, 2027.
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Quick answers
Selected conversion
1:00 pm13:00 BST (UTC+1), Oct 13, 2026 = 1:45 am01:45 CHADT (UTC+13:45), Oct 14, 2026
BST is 12 hours and 45 minutes behind CHADT.
BST and CHAST examples
These examples always use BST (UTC+1) and CHAST (UTC+12:45). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
BST is 11 hours and 45 minutes behind CHAST.
How the time difference changes
Depending on seasonal clock changes, BST is 11 hours and 45 minutes behind CHAST, BST is 12 hours and 45 minutes behind CHADT, or GMT is 13 hours and 45 minutes behind CHADT.
Depending on seasonal clock changes, working hours of 9:00 am to 5:00 pm in BST correspond to 8:45 pm to 4:45 am (next day) in CHAST, working hours of 9:00 am to 5:00 pm in BST correspond to 9:45 pm to 5:45 am (next day) in CHADT, or working hours of 9:00 am to 5:00 pm in GMT correspond to 10:45 pm to 6:45 am (next day) in CHADT.Depending on seasonal clock changes, working hours of 09:00 to 17:00 in BST correspond to 20:45 to 04:45 (next day) in CHAST, working hours of 09:00 to 17:00 in BST correspond to 21:45 to 05:45 (next day) in CHADT, or working hours of 09:00 to 17:00 in GMT correspond to 22:45 to 06:45 (next day) in CHADT.
Compare BST time with CHAST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
British Summer Time is 12 hours and 45 minutes behind Chatham Island Daylight Time.
1:00 pm13:00 in BST is 1:45 am01:45 in CHADT
BST to CHADT call time
Best time for a conference call or a meeting is between 6:15pm-7:15pm18:15-19:15 in BST which corresponds to 7am-8am07:00-08:00 in CHADT (next day). Their 9am–5pm09:00–17:00 working hours do not overlap; this is a suggested compromise.
1:00 pm13:00 British Summer Time (BST). Offset UTC +1:00 hour
1:45 am01:45 Chatham Island Daylight Time (CHADT). Offset UTC +13:45 hours
1:00 pm13:00 BST / 1:45 am01:45 CHADT
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
| BST | CHADT |
|---|---|
| 12:45pm | |
| 1:45pm | |
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British Summer Time
Offset: BST is 1 hour ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Britain (UK), Guernsey, Isle of Man, Jersey
Principal Cities: The largest city in the BST time zone is London in the United Kingdom, with about 8.962 million people. Other major cities in this time zone include Birmingham, Glasgow, Manchester, Sheffield.
Today all shaded areas are on BST.
Daylight Saving: British Summer Time (BST) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Greenwich Mean Time (GMT).
Start: British Summer Time (BST) started on Sunday, March 29, 2026 at 1:00 am01:00 local time and clocks were set one hour forward to Sunday, March 29, 2026, 2:00 am02:00. Daylight saving starts annually on the last Sunday of March.
End: British Summer Time (BST) ends on Sunday, October 25, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, October 25, 2026, 1:00 am01:00 local standard time instead. Daylight saving ends annually on the last Sunday of October.
BST representations, usage and related time zones
- +01 - basic short
- +0100 - basic
- +01:00 - extended
- +0100 - sign character (+) followed by a four digit time providing hours (01) and minutes (00) of the offset. Indicates an offset of one hour to the east of the zero meridian.
- Alpha - Military abbreviation for BST
- A - short form of 'Alpha'
- Europe/Belfast
- Europe/Guernsey
- Europe/Isle_of_Man
- Europe/Jersey
- Europe/London
- GB
- GB-Eire
- British Summer Time - UTC +1
- Bangladesh Standard Time - UTC +6
- Bougainville Standard Time - UTC +11
- BST - British Summer Time
- CET - Central European Time
- IST - Irish Standard Time
- WEST - Western European Summer Time
- A - Alpha Time Zone
- CET - Central European Time
- MEZ - Mitteleuropäische Zeit
- WAT - West Africa Time
- WST - Western Sahara Summer Time
- BMT - Biel Mean Time
Chatham Island Standard Time
Offset: CHAST is 12 hours and 45 minutes ahead of Greenwich Mean Time (GMT).
Countries using this time zone: New Zealand
Principal Cities: The largest city in the CHAST time zone is Waitangi in New Zealand, with about 140 people.
Today the shaded areas are on UTC+13:45.
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Chatham Island Daylight Time (CHADT).
End: Chatham Island Standard Time (CHAST) ended on Sunday, September 27, 2026 at 2:45 am02:45 local time and clocks were set one hour forward to Sunday, September 27, 2026, 3:45 am03:45 local daylight time instead. Standard time ends annually on the last Sunday of September.
Start: Chatham Island Standard Time (CHAST) starts on Sunday, April 4, 2027 at 3:45 am03:45 local time and clocks are set one hour back to Sunday, April 4, 2027, 2:45 am02:45. Standard time starts annually on the first Sunday of April.
CHAST representations, usage and related time zones
- +1245 - basic
- +12:45 - extended
- +1245 - sign character (+) followed by a four digit time providing hours (12) and minutes (45) of the offset. Indicates an offset of twelve hours and forty-five minutes to the east of the zero meridian.