COT to ET Time Converter
ET is 1 hour ahead of COT. COT is UTC-5:00, and The US East Coast is currently on EDT (UTC-4:00).
Best Time to Call Between COT and ET
Both zones are inside normal business hours between 9:00 AM and 4:00 PM COT — that's 10:00 AM to 5:00 PM ET. That's a 7-hour window.
both at work COT only ET only neither — hours along the strip are COT.
Common Times Converted
COT on the left, ET on the right.
COT to ET: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| COT | ET | Working hours |
|---|---|---|
| 12:00 AM | 1:00 AM | — |
| 1:00 AM | 2:00 AM | — |
| 2:00 AM | 3:00 AM | — |
| 3:00 AM | 4:00 AM | — |
| 4:00 AM | 5:00 AM | — |
| 5:00 AM | 6:00 AM | — |
| 6:00 AM | 7:00 AM | — |
| 7:00 AM | 8:00 AM | — |
| 8:00 AM | 9:00 AM | ET only |
| 9:00 AM | 10:00 AM | Both zones |
| 10:00 AM | 11:00 AM | Both zones |
| 11:00 AM | 12:00 PM | Both zones |
| 12:00 PM | 1:00 PM | Both zones |
| 1:00 PM | 2:00 PM | Both zones |
| 2:00 PM | 3:00 PM | Both zones |
| 3:00 PM | 4:00 PM | Both zones |
| 4:00 PM | 5:00 PM | COT only |
| 5:00 PM | 6:00 PM | — |
| 6:00 PM | 7:00 PM | — |
| 7:00 PM | 8:00 PM | — |
| 8:00 PM | 9:00 PM | — |
| 9:00 PM | 10:00 PM | — |
| 10:00 PM | 11:00 PM | — |
| 11:00 PM | 12:00 AM next day | — |
What COT and ET 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.
ET — Eastern Time
New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-5:00 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, November 1, 2026, to EST.
Eastern Time covers roughly half the US population and, because of that, is the zone most American business defaults to when nobody specifies one.
What This Means in Practice
This gap is not fixed
ET 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, November 1, 2026 unless someone resets it.
Close enough to share a working day
At only 1 hour apart, the two working days overlap almost completely. Scheduling is barely constrained by the difference.
Major Cities in Each Zone
Cities on COT
Cities on ET
Frequently Asked Questions
What is the time difference between COT and ET?
ET is 1 hour ahead of COT. That is the live figure. Taken strictly as written, the gap between COT and ET is — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM COT in ET?
9:00 AM COT is 10:00 AM ET.
What are the best hours to schedule a call between COT and ET?
Between 9:00 AM and 4:00 PM COT, which is 10:00 AM to 5:00 PM ET. Both sides are inside normal business hours through that window.
Does the difference between COT and ET change during the year?
Yes. ET 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, November 1, 2026.