Time in BST and COST
The time difference between Bougainville Standard Time (BST) and Colombia Summer Time (COST) is 15 hours. Colombia Summer Time is 15 hours behind Bougainville Standard Time.
This means 9am BST is 6pm COST (previous day) and 5pm BST is 2am COST.
Bougainville Standard Time
- The current local time in BST is 12:38 am (July 19, 2026)
- BST time zone offset is UTC+11:00
Colombia Summer Time
- The current local time in COST is 5:38 pm (July 18, 2026)
- COST time zone offset is UTC-04:00
How to convert Bougainville Standard Time to Colombia Summer Time?
Subtract 15 hours from Bougainville Standard Time to get Colombia Summer Time.
Time in BST
00:00
Time in COST
00:00
Use the slider above to convert Bougainville Standard Time to Colombia Summer 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 | COST |
|---|---|
| 12am | 9am |
| 1am | 10am |
| 2am | 11am |
| 3am | 12pm |
| 4am | 1pm |
| 5am | 2pm |
| 6am | 3pm |
| 7am | 4pm |
| 8am | 5pm |
| 9am | 6pm |
| 10am | 7pm |
| 11am | 8pm |
| 12pm | 9pm |
| 1pm | 10pm |
| 2pm | 11pm |
| 3pm | 12am |
| 4pm | 1am |
| 5pm | 2am |
| 6pm | 3am |
| 7pm | 4am |
| 8pm | 5am |
| 9pm | 6am |
| 10pm | 7am |
| 11pm | 8am |