COT to HST Time Converter
HST is 5 hours behind COT. COT is UTC-5:00, and HST is UTC-10:00.
Best Time to Call Between COT and HST
Both zones are inside normal business hours between 2:00 PM and 5:00 PM COT — that's 9:00 AM to 12:00 PM HST. That's a 3-hour window.
both at work COT only HST only neither — hours along the strip are COT.
Common Times Converted
COT on the left, HST on the right.
COT to HST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| COT | HST | Working hours |
|---|---|---|
| 12:00 AM | 7:00 PM prev day | — |
| 1:00 AM | 8:00 PM prev day | — |
| 2:00 AM | 9:00 PM prev day | — |
| 3:00 AM | 10:00 PM prev day | — |
| 4:00 AM | 11:00 PM prev day | — |
| 5:00 AM | 12:00 AM | — |
| 6:00 AM | 1:00 AM | — |
| 7:00 AM | 2:00 AM | — |
| 8:00 AM | 3:00 AM | — |
| 9:00 AM | 4:00 AM | COT only |
| 10:00 AM | 5:00 AM | COT only |
| 11:00 AM | 6:00 AM | COT only |
| 12:00 PM | 7:00 AM | COT only |
| 1:00 PM | 8:00 AM | COT only |
| 2:00 PM | 9:00 AM | Both zones |
| 3:00 PM | 10:00 AM | Both zones |
| 4:00 PM | 11:00 AM | Both zones |
| 5:00 PM | 12:00 PM | HST only |
| 6:00 PM | 1:00 PM | HST only |
| 7:00 PM | 2:00 PM | HST only |
| 8:00 PM | 3:00 PM | HST only |
| 9:00 PM | 4:00 PM | HST only |
| 10:00 PM | 5:00 PM | — |
| 11:00 PM | 6:00 PM | — |
What COT and HST 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.
HST — Hawaii Standard Time
Honolulu and the rest of Hawaii. Standing at UTC-10:00 as written, and the region does not change its clocks, so that offset holds all year. Hawaii does not observe daylight saving, so this offset holds all year.
Hawaii dropped daylight saving in 1967 and never resumed it. Being close to the equator, its daylight barely varies across the year, so there is little to gain.
What This Means in Practice
A gap you can rely on
Neither region changes its clocks, so this difference holds every day of the year. A recurring meeting booked once stays correct — worth knowing, because most cross-border pairs cannot say that.
Major Cities in Each Zone
Cities on COT
Cities on HST
Frequently Asked Questions
What is the time difference between COT and HST?
HST is 5 hours behind COT.
What is 9:00 AM COT in HST?
9:00 AM COT is 4:00 AM HST.
What are the best hours to schedule a call between COT and HST?
Between 2:00 PM and 5:00 PM COT, which is 9:00 AM to 12:00 PM HST. Both sides are inside normal business hours through that window.
Does the difference between COT and HST change during the year?
No. Neither region changes its clocks, so this gap is fixed all year round.
Does HST always mean Hawaii Standard Time?
Hawaii does not observe daylight saving, so this offset holds all year.