CAT to HST Time Converter
HST is 12 hours behind CAT. CAT is UTC+2:00, and HST is UTC-10:00.
Best Time to Call Between CAT and HST
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 7:00 AM to 10:00 AM CAT, which is 7:00 PM to 10:00 PM HST.
both at work CAT only HST only neither — hours along the strip are CAT.
Common Times Converted
CAT on the left, HST on the right.
CAT to HST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| CAT | HST | Working hours |
|---|---|---|
| 12:00 AM | 12:00 PM prev day | HST only |
| 1:00 AM | 1:00 PM prev day | HST only |
| 2:00 AM | 2:00 PM prev day | HST only |
| 3:00 AM | 3:00 PM prev day | HST only |
| 4:00 AM | 4:00 PM prev day | HST only |
| 5:00 AM | 5:00 PM prev day | — |
| 6:00 AM | 6:00 PM prev day | — |
| 7:00 AM | 7:00 PM prev day | — |
| 8:00 AM | 8:00 PM prev day | — |
| 9:00 AM | 9:00 PM prev day | CAT only |
| 10:00 AM | 10:00 PM prev day | CAT only |
| 11:00 AM | 11:00 PM prev day | CAT only |
| 12:00 PM | 12:00 AM | CAT only |
| 1:00 PM | 1:00 AM | CAT only |
| 2:00 PM | 2:00 AM | CAT only |
| 3:00 PM | 3:00 AM | CAT only |
| 4:00 PM | 4:00 AM | CAT only |
| 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 | HST only |
| 10:00 PM | 10:00 AM | HST only |
| 11:00 PM | 11:00 AM | HST only |
What CAT and HST Actually Are
CAT — Central Africa Time
Harare, Lusaka, Maputo, Khartoum. Standing at UTC+2:00 as written, and the region does not change its clocks, so that offset holds all year.
Central Africa Time has never used daylight saving. Near the equator the length of the day changes so little that there would be nothing to shift.
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
The date changes mid-working-day
For 3 of the eight hours in a normal CAT working day, the equivalent HST 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 12 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 CAT
Cities on HST
Frequently Asked Questions
What is the time difference between CAT and HST?
HST is 12 hours behind CAT.
What is 9:00 AM CAT in HST?
9:00 AM CAT is 9:00 PM the previous day HST.
What are the best hours to schedule a call between CAT and HST?
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 7:00 AM to 10:00 AM CAT, which is 7:00 PM to 10:00 PM HST.
Does the difference between CAT 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.