HST to EAT Time Converter
EAT is 13 hours ahead of HST. HST is UTC-10:00, and EAT is UTC+3:00.
Best Time to Call Between HST and EAT
Standard 9-to-5 hours in these two zones never overlap, so someone has to take the call outside their working day. The most workable window is 6:00 PM to 10:00 PM HST, which is 7:00 AM to 11:00 AM EAT.
both at work HST only EAT only neither — hours along the strip are HST.
Common Times Converted
HST on the left, EAT on the right.
HST to EAT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| HST | EAT | Working hours |
|---|---|---|
| 12:00 AM | 1:00 PM | EAT only |
| 1:00 AM | 2:00 PM | EAT only |
| 2:00 AM | 3:00 PM | EAT only |
| 3:00 AM | 4:00 PM | EAT only |
| 4:00 AM | 5:00 PM | — |
| 5:00 AM | 6:00 PM | — |
| 6:00 AM | 7:00 PM | — |
| 7:00 AM | 8:00 PM | — |
| 8:00 AM | 9:00 PM | — |
| 9:00 AM | 10:00 PM | HST only |
| 10:00 AM | 11:00 PM | HST only |
| 11:00 AM | 12:00 AM next day | HST only |
| 12:00 PM | 1:00 AM next day | HST only |
| 1:00 PM | 2:00 AM next day | HST only |
| 2:00 PM | 3:00 AM next day | HST only |
| 3:00 PM | 4:00 AM next day | HST only |
| 4:00 PM | 5:00 AM next day | HST only |
| 5:00 PM | 6:00 AM next day | — |
| 6:00 PM | 7:00 AM next day | — |
| 7:00 PM | 8:00 AM next day | — |
| 8:00 PM | 9:00 AM next day | EAT only |
| 9:00 PM | 10:00 AM next day | EAT only |
| 10:00 PM | 11:00 AM next day | EAT only |
| 11:00 PM | 12:00 PM next day | EAT only |
What HST and EAT Actually Are
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.
EAT — East Africa Time
Nairobi, Addis Ababa, Dar es Salaam, Kampala, Mogadishu. Standing at UTC+3:00 as written, and the region does not change its clocks, so that offset holds all year.
East Africa Time is shared by a run of countries down the Rift Valley, and Ethiopia additionally keeps a traditional 12-hour clock that starts counting at dawn.
What This Means in Practice
The date changes mid-working-day
For 6 of the eight hours in a normal HST working day, the equivalent EAT time falls on a different calendar date. Anything scheduled in that stretch needs the date checked as well as the time, or a Tuesday call quietly becomes a Wednesday one at the other end.
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.
Nearly opposite sides of the clock
At 13 hours apart, one side's morning is the other side's night. Handing work over at the end of a shift usually beats trying to get both parties in the same call.
Major Cities in Each Zone
Cities on HST
Cities on EAT
Frequently Asked Questions
What is the time difference between HST and EAT?
EAT is 13 hours ahead of HST.
What is 9:00 AM HST in EAT?
9:00 AM HST is 10:00 PM EAT.
What are the best hours to schedule a call between HST and EAT?
Standard business hours in these two zones do not overlap at all, so one side has to work outside the 9-to-5. The most workable window is 6:00 PM to 10:00 PM HST, which is 7:00 AM to 11:00 AM EAT.
Does the difference between HST and EAT 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.