GST to HST Time Converter
HST is 14 hours behind GST. GST is UTC+4:00, and HST is UTC-10:00.
Best Time to Call Between GST 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 12:00 PM GST, which is 5:00 PM to 10:00 PM HST.
both at work GST only HST only neither — hours along the strip are GST.
Common Times Converted
GST on the left, HST on the right.
GST to HST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| GST | HST | Working hours |
|---|---|---|
| 12:00 AM | 10:00 AM prev day | HST only |
| 1:00 AM | 11:00 AM prev day | HST only |
| 2:00 AM | 12:00 PM prev day | HST only |
| 3:00 AM | 1:00 PM prev day | HST only |
| 4:00 AM | 2:00 PM prev day | HST only |
| 5:00 AM | 3:00 PM prev day | HST only |
| 6:00 AM | 4:00 PM prev day | HST only |
| 7:00 AM | 5:00 PM prev day | — |
| 8:00 AM | 6:00 PM prev day | — |
| 9:00 AM | 7:00 PM prev day | GST only |
| 10:00 AM | 8:00 PM prev day | GST only |
| 11:00 AM | 9:00 PM prev day | GST only |
| 12:00 PM | 10:00 PM prev day | GST only |
| 1:00 PM | 11:00 PM prev day | GST only |
| 2:00 PM | 12:00 AM | GST only |
| 3:00 PM | 1:00 AM | GST only |
| 4:00 PM | 2:00 AM | GST only |
| 5:00 PM | 3:00 AM | — |
| 6:00 PM | 4:00 AM | — |
| 7:00 PM | 5:00 AM | — |
| 8:00 PM | 6:00 AM | — |
| 9:00 PM | 7:00 AM | — |
| 10:00 PM | 8:00 AM | — |
| 11:00 PM | 9:00 AM | HST only |
What GST and HST Actually Are
GST — Gulf Standard Time
Dubai, Abu Dhabi, Sharjah, Muscat. Standing at UTC+4:00 as written, and the region does not change its clocks, so that offset holds all year. GST also refers to South Georgia Time (UTC-2), which you are very unlikely to want.
The Gulf states have never observed daylight saving, so Dubai's offset has been unchanged for decades — unusual stability for a region that grew as fast as it did.
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 5 of the eight hours in a normal GST 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 14 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 GST
Cities on HST
Frequently Asked Questions
What is the time difference between GST and HST?
HST is 14 hours behind GST.
What is 9:00 AM GST in HST?
9:00 AM GST is 7:00 PM the previous day HST.
What are the best hours to schedule a call between GST 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 12:00 PM GST, which is 5:00 PM to 10:00 PM HST.
Does the difference between GST and HST change during the year?
No. Neither region changes its clocks, so this gap is fixed all year round.
Does GST always mean Gulf Standard Time?
GST also refers to South Georgia Time (UTC-2), which you are very unlikely to want.
Does HST always mean Hawaii Standard Time?
Hawaii does not observe daylight saving, so this offset holds all year.