COT to GMT Time Converter
GMT is 6 hours ahead of COT. COT is UTC-5:00, and The UK and Ireland are currently on BST (UTC+1:00).
Best Time to Call Between COT and GMT
Both zones are inside normal business hours between 9:00 AM and 11:00 AM COT — that's 3:00 PM to 5:00 PM GMT. That's a 2-hour window.
both at work COT only GMT only neither — hours along the strip are COT.
Common Times Converted
COT on the left, GMT on the right.
COT to GMT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| COT | GMT | Working hours |
|---|---|---|
| 12:00 AM | 6:00 AM | — |
| 1:00 AM | 7:00 AM | — |
| 2:00 AM | 8:00 AM | — |
| 3:00 AM | 9:00 AM | GMT only |
| 4:00 AM | 10:00 AM | GMT only |
| 5:00 AM | 11:00 AM | GMT only |
| 6:00 AM | 12:00 PM | GMT only |
| 7:00 AM | 1:00 PM | GMT only |
| 8:00 AM | 2:00 PM | GMT only |
| 9:00 AM | 3:00 PM | Both zones |
| 10:00 AM | 4:00 PM | Both zones |
| 11:00 AM | 5:00 PM | COT only |
| 12:00 PM | 6:00 PM | COT only |
| 1:00 PM | 7:00 PM | COT only |
| 2:00 PM | 8:00 PM | COT only |
| 3:00 PM | 9:00 PM | COT only |
| 4:00 PM | 10:00 PM | COT only |
| 5:00 PM | 11:00 PM | — |
| 6:00 PM | 12:00 AM next day | — |
| 7:00 PM | 1:00 AM next day | — |
| 8:00 PM | 2:00 AM next day | — |
| 9:00 PM | 3:00 AM next day | — |
| 10:00 PM | 4:00 AM next day | — |
| 11:00 PM | 5:00 AM next day | — |
What COT and GMT Actually Are
COT — Colombia Time
Bogotá, Medellín, Cali, Barranquilla. Standing at UTC-5:00 as written, and the region does not change its clocks, so that offset holds all year.
Colombia briefly tried daylight saving during the energy crisis of 1992-93 and has not repeated it.
GMT — Greenwich Mean Time
The UK and Ireland in winter, plus Iceland, Portugal and much of West Africa. Standing at UTC as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, October 25, 2026, to GMT. Often used loosely as a synonym for UTC. They differ by less than a second, so for scheduling they are interchangeable.
Britain ran an experiment from 1968 to 1971 on permanent UTC+1, abandoning GMT entirely. It was scrapped after complaints about dark winter mornings in Scotland.
What This Means in Practice
This gap is not fixed
GMT changes its clocks and COT does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, October 25, 2026 unless someone resets it.
Major Cities in Each Zone
Cities on COT
Cities on GMT
Frequently Asked Questions
What is the time difference between COT and GMT?
GMT is 6 hours ahead of COT. That is the live figure. Taken strictly as written, the gap between COT and GMT is 5 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM COT in GMT?
9:00 AM COT is 3:00 PM GMT.
What are the best hours to schedule a call between COT and GMT?
Between 9:00 AM and 11:00 AM COT, which is 3:00 PM to 5:00 PM GMT. Both sides are inside normal business hours through that window.
Does the difference between COT and GMT change during the year?
Yes. GMT observes daylight saving and COT does not, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, October 25, 2026.
Does GMT always mean Greenwich Mean Time?
Often used loosely as a synonym for UTC. They differ by less than a second, so for scheduling they are interchangeable.