Time in BST and IDLW
The time difference between British Summer Time (BST) and International Date Line West Time (IDLW) is 13 hours. International Date Line West Time is 13 hours behind British Summer Time.
This means 9am BST is 8pm IDLW (previous day) and 5pm BST is 4am IDLW.
British Summer Time
- The current local time in BST is 2:10 pm (July 3, 2026)
- BST time zone offset is UTC+01:00
International Date Line West Time
- The current local time in IDLW is 1:10 am (July 4, 2026)
- IDLW time zone offset is UTC-12:00
How to convert British Summer Time to International Date Line West Time?
Subtract 13 hours from British Summer Time to get International Date Line West Time.
Time in BST
00:00
Time in IDLW
00:00
Use the slider above to convert British Summer Time to International Date Line West Time and view the day and night map at different times.
Day–night colors on the map:
Day
Civil twilight
Nautical twilight
Astronomical twilight
NightTime Conversion Chart
| BST | IDLW |
|---|---|
| 12am | 11am |
| 1am | 12pm |
| 2am | 1pm |
| 3am | 2pm |
| 4am | 3pm |
| 5am | 4pm |
| 6am | 5pm |
| 7am | 6pm |
| 8am | 7pm |
| 9am | 8pm |
| 10am | 9pm |
| 11am | 10pm |
| 12pm | 11pm |
| 1pm | 12am |
| 2pm | 1am |
| 3pm | 2am |
| 4pm | 3am |
| 5pm | 4am |
| 6pm | 5am |
| 7pm | 6am |
| 8pm | 7am |
| 9pm | 8am |
| 10pm | 9am |
| 11pm | 10am |