GMT to COT Time Converter
COT is 6 hours behind GMT. The UK and Ireland are currently on BST (UTC+1:00), and COT is UTC-5:00.
Best Time to Call Between GMT and COT
Both zones are inside normal business hours between 3:00 PM and 5:00 PM GMT — that's 9:00 AM to 11:00 AM COT. That's a 2-hour window.
both at work GMT only COT only neither — hours along the strip are GMT.
Common Times Converted
GMT on the left, COT on the right.
GMT to COT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| GMT | COT | Working hours |
|---|---|---|
| 12:00 AM | 6:00 PM prev day | — |
| 1:00 AM | 7:00 PM prev day | — |
| 2:00 AM | 8:00 PM prev day | — |
| 3:00 AM | 9:00 PM prev day | — |
| 4:00 AM | 10:00 PM prev day | — |
| 5:00 AM | 11:00 PM prev day | — |
| 6:00 AM | 12:00 AM | — |
| 7:00 AM | 1:00 AM | — |
| 8:00 AM | 2:00 AM | — |
| 9:00 AM | 3:00 AM | GMT only |
| 10:00 AM | 4:00 AM | GMT only |
| 11:00 AM | 5:00 AM | GMT only |
| 12:00 PM | 6:00 AM | GMT only |
| 1:00 PM | 7:00 AM | GMT only |
| 2:00 PM | 8:00 AM | GMT only |
| 3:00 PM | 9:00 AM | Both zones |
| 4:00 PM | 10:00 AM | Both zones |
| 5:00 PM | 11:00 AM | COT only |
| 6:00 PM | 12:00 PM | COT only |
| 7:00 PM | 1:00 PM | COT only |
| 8:00 PM | 2:00 PM | COT only |
| 9:00 PM | 3:00 PM | COT only |
| 10:00 PM | 4:00 PM | COT only |
| 11:00 PM | 5:00 PM | — |
What GMT and COT Actually Are
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.
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.
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 GMT
Cities on COT
Frequently Asked Questions
What is the time difference between GMT and COT?
COT is 6 hours behind GMT. That is the live figure. Taken strictly as written, the gap between GMT and COT is 5 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM GMT in COT?
9:00 AM GMT is 3:00 AM COT.
What are the best hours to schedule a call between GMT and COT?
Between 3:00 PM and 5:00 PM GMT, which is 9:00 AM to 11:00 AM COT. Both sides are inside normal business hours through that window.
Does the difference between GMT and COT 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.