BST to Y Converter
Start by searching for a time zone, city, or town.
Add one or more places to compare local times, adjust the date, and share the result.
Quick answers
Selected conversion
12:00 pm12:00 GMT (UTC+0), Oct 28, 2026 = 12:00 am00:00 Y (UTC-12), Oct 28, 2026
GMT is 12 hours ahead of Y.
BST and Y examples
These examples always use BST (UTC+1) and Y (UTC-12). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
BST is 13 hours ahead of Y.
How the time difference changes
For most of the year, BST is 13 hours ahead of Y. From Oct 25, 2026 to Mar 28, 2027, GMT is 12 hours ahead of Y.
For most of the year, working hours of 9:00 am to 6:00 pm in BST correspond to 8:00 pm (previous day) to 5:00 am in Y. At other times of the year, working hours of 9:00 am to 6:00 pm in GMT correspond to 9:00 pm (previous day) to 6:00 am in Y.For most of the year, working hours of 09:00 to 18:00 in BST correspond to 20:00 (previous day) to 05:00 in Y. At other times of the year, working hours of 09:00 to 18:00 in GMT correspond to 21:00 (previous day) to 06:00 in Y.
Compare BST time with Y time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Greenwich Mean Time is 12 hours ahead of Yankee Time Zone.
12:00 pm12:00 in GMT is 12:00 am00:00 in Y
GMT to Y call time
Best time for a conference call or a meeting is between 7am-8am07:00-08:00 in GMT which corresponds to 7pm-8pm19:00-20:00 in Y (previous day). Their 9am–6pm09:00–18:00 working hours do not overlap; this is a suggested compromise.
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
12:00 am00:00 Yankee Time Zone (Y). Offset UTC -12:00 hours
12:00 pm12:00 GMT / 12:00 am00:00 Y
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.
| GMT | Y |
|---|---|
| 12:00pm previous day | |
| 1:00pm previous day | |
| 2:00pm previous day | |
| 3:00pm previous day | |
| 4:00pm previous day | |
| 5:00pm previous day | |
| 6:00pm previous day | |
| 7:00pm previous day | |
| 8:00pm previous day | |
| 9:00pm previous day | |
| 10:00pm previous day | |
| 11:00pm previous day | |
| 12:00am | |
| 1:00am | |
| 2:00am | |
| 3:00am | |
| 4:00am | |
| 5:00am | |
| 6:00am | |
| 7:00am | |
| 8:00am | |
| 9:00am | |
| 10:00am | |
| 11:00am | |
| 12:00 previous day | |
| 13:00 previous day | |
| 14:00 previous day | |
| 15:00 previous day | |
| 16:00 previous day | |
| 17:00 previous day | |
| 18:00 previous day | |
| 19:00 previous day | |
| 20:00 previous day | |
| 21:00 previous day | |
| 22:00 previous day | |
| 23:00 previous day | |
| 00:00 | |
| 01:00 | |
| 02:00 | |
| 03:00 | |
| 04:00 | |
| 05:00 | |
| 06:00 | |
| 07:00 | |
| 08:00 | |
| 09:00 | |
| 10:00 | |
| 11:00 |
British Summer Time
Offset: BST is 1 hour ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Guernsey, Isle of Man, Jersey, United Kingdom
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.
Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use the two are the same. In the military, GMT is known as Zulu time. Greenwich Mean Time was the same as Universal Time (UT), a standard astronomical concept used in many technical fields, until the introduction of UTC in 1972.
Current time in the United Kingdom: UK time now
Today the shaded areas are on UTC+0 (GMT).
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
Yankee Time Zone
Offset: Y is 12 hours behind Greenwich Mean Time (GMT).
Daylight Saving: Clocks in Yankee Time Zone (Y) do not change for daylight saving time, so Y stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.
Y representations, usage and related time zones
- -12 - basic short
- -1200 - basic
- -12:00 - extended
- -1200 - sign character (-) followed by a four digit time providing hours (12) and minutes (00) of the offset. Indicates an offset of twelve hours to the west of the zero meridian.
- Yankee - Military abbreviation for Y
- Y - short form of 'Yankee'