Convert HST to KST
KST is 19 hours ahead of HST. HST is UTC−10 and KST is UTC+9.
Right now: HST · KST
Best time to schedule a meeting
Standard 9–5 working hours do not overlap at all between HST and KST. Someone has to take an early or late call — or use asynchronous communication instead.
| HST | KST | Suitable? |
|---|---|---|
| 9:00 AM | 4:00 AM (next day) | outside 9–5 |
| 10:00 AM | 5:00 AM (next day) | outside 9–5 |
| 11:00 AM | 6:00 AM (next day) | outside 9–5 |
| 12:00 PM | 7:00 AM (next day) | outside 9–5 |
| 1:00 PM | 8:00 AM (next day) | outside 9–5 |
| 2:00 PM | 9:00 AM (next day) | outside 9–5 |
| 3:00 PM | 10:00 AM (next day) | outside 9–5 |
| 4:00 PM | 11:00 AM (next day) | outside 9–5 |
| 5:00 PM | 12:00 PM (next day) | outside 9–5 |
HST to KST conversion table
| HST | KST |
|---|---|
| 12:00 AM | 7:00 PM |
| 1:00 AM | 8:00 PM |
| 2:00 AM | 9:00 PM |
| 3:00 AM | 10:00 PM |
| 4:00 AM | 11:00 PM |
| 5:00 AM | 12:00 AM (next day) |
| 6:00 AM | 1:00 AM (next day) |
| 7:00 AM | 2:00 AM (next day) |
| 8:00 AM | 3:00 AM (next day) |
| 9:00 AM | 4:00 AM (next day) |
| 10:00 AM | 5:00 AM (next day) |
| 11:00 AM | 6:00 AM (next day) |
| 12:00 PM | 7:00 AM (next day) |
| 1:00 PM | 8:00 AM (next day) |
| 2:00 PM | 9:00 AM (next day) |
| 3:00 PM | 10:00 AM (next day) |
| 4:00 PM | 11:00 AM (next day) |
| 5:00 PM | 12:00 PM (next day) |
| 6:00 PM | 1:00 PM (next day) |
| 7:00 PM | 2:00 PM (next day) |
| 8:00 PM | 3:00 PM (next day) |
| 9:00 PM | 4:00 PM (next day) |
| 10:00 PM | 5:00 PM (next day) |
| 11:00 PM | 6:00 PM (next day) |
About HST
Hawaii Standard Time (HST) is UTC−10. It is used in Hawaii, which does not observe daylight saving at all.
About KST
Korea Standard Time (KST) is UTC+9. It is used in South Korea, with no daylight saving.
A warning about daylight saving
The abbreviations on this page each denote a single fixed offset, so every figure here is exact. What changes is which abbreviation a place uses. New York is on EST in January and EDT in July, so "New York time" moves by an hour twice a year while EST and EDT themselves never move. When you schedule across zones, name the city rather than the abbreviation, or use UTC — that is what calendar software does internally.
Frequently asked questions
What time is 9:00 AM HST in KST?
9:00 AM HST is 4:00 AM KST (next day).
Is KST ahead of HST?
KST is 19 hours ahead of HST.
Which time zone does this use?
HST is UTC−10 and KST is UTC+9. Both abbreviations denote a single fixed offset, so this conversion never shifts with daylight saving — what changes is which abbreviation a place is using at the time.