HST to JST Converter & Meeting Planner
Quick answer: 9:00 AM HST = 4:00 AM JST (fixed -10:00 standard offset — not DST-adjusted). Use the interactive converter below for DST-aware local-time scheduling.
Planning a call or meeting between Hawaii-Aleutian Standard Time (HST) and Japan Standard Time (JST)? You need to account for the standard time difference. Japan Standard Time is normally 19 hours ahead of Hawaii-Aleutian Standard Time. Whether you are coordinating between teams in Honolulu and Hilo and Tokyo and Osaka, our live tool has you covered. Use our interactive overlap studio below to find the perfect waking hours for both regions, taking into account any seasonal Daylight Saving Time (DST) changes.
24-Hour Conversion Table
Quick reference: 12:00 AM HST = 7:00 PM JST. The full 24-hour HST to JST table below uses fixed standard offsets for exact abbreviation searches.
Example: 3:00 PM HST = 10:00 AM JST (+1 day).
| HST Time | JST Time |
|---|---|
| 12:00 AM (00:00) | 7:00 PM (19:00) |
| 1:00 AM (01:00) | 8:00 PM (20:00) |
| 2:00 AM (02:00) | 9:00 PM (21:00) |
| 3:00 AM (03:00) | 10:00 PM (22:00) |
| 4:00 AM (04:00) | 11:00 PM (23:00) |
| 5:00 AM (05:00) | 12:00 AM (00:00)+1 day |
| 6:00 AM (06:00) | 1:00 AM (01:00)+1 day |
| 7:00 AM (07:00) | 2:00 AM (02:00)+1 day |
| 8:00 AM (08:00) | 3:00 AM (03:00)+1 day |
| 9:00 AM (09:00) | 4:00 AM (04:00)+1 day |
| 10:00 AM (10:00) | 5:00 AM (05:00)+1 day |
| 11:00 AM (11:00) | 6:00 AM (06:00)+1 day |
| 12:00 PM (12:00) | 7:00 AM (07:00)+1 day |
| 1:00 PM (13:00) | 8:00 AM (08:00)+1 day |
| 2:00 PM (14:00) | 9:00 AM (09:00)+1 day |
| 3:00 PM (15:00) | 10:00 AM (10:00)+1 day |
| 4:00 PM (16:00) | 11:00 AM (11:00)+1 day |
| 5:00 PM (17:00) | 12:00 PM (12:00)+1 day |
| 6:00 PM (18:00) | 1:00 PM (13:00)+1 day |
| 7:00 PM (19:00) | 2:00 PM (14:00)+1 day |
| 8:00 PM (20:00) | 3:00 PM (15:00)+1 day |
| 9:00 PM (21:00) | 4:00 PM (16:00)+1 day |
| 10:00 PM (22:00) | 5:00 PM (17:00)+1 day |
| 11:00 PM (23:00) | 6:00 PM (18:00)+1 day |
Best time to call Tokyo from Honolulu
For most work calls, compare the normal business day in Honolulu (HST) with the business day in Tokyo (JST). HST commonly covers Pacific Ocean, North America, while JST is mainly associated with East Asia.
⚠️ Note: 2026-07-05 is not a normal workday in one or both regions based on their configured calendar. The overlap below should be treated as a reference, not a guaranteed office-hours window.
✅ The most practical overlap on 2026-07-05 is usually 2:00 PM - 5:00 PM HST, which corresponds to 9:00 AM - 12:00 PM JST. This window sits inside the typical HST workday (9:00 AM - 5:00 PM) and the JST workday (9:00 AM - 6:00 PM).
- DST Safety: HST or JST may shift during Daylight Saving Time. Always confirm the converted time for your specific date.
- Tokyo Stock Exchange (TSE): 09:00-15:00 local time in Tokyo.
🔥 Popular HST & JST Converters
Frequently searched time zone conversions related to your search.
Related Time Converters
Explore nearby time zone offsets and reverse conversions related to HST and JST.
Frequently Asked Questions
What is the time difference between HST and JST?
During standard time, Japan Standard Time is 19 hours ahead of Hawaii-Aleutian Standard Time.
Does Hawaii observe Daylight Saving Time?
Hawaii does not observe Daylight Saving Time and has not done so since 1947, remaining fixed at UTC-10:00 year-round. At roughly 20° North latitude, Hawaii's daylight hours vary by only about 1.5 hours between the summer and winter solstices — far too little to justify the disruption of a seasonal clock change.
Why is it called Hawaii-Aleutian time?
The name combines two geographically distant US territories that share the same UTC-10:00 standard offset: the Hawaiian Islands in the central Pacific and the westernmost Aleutian Islands of Alaska, which extend past the 180° meridian into the Eastern Hemisphere. Despite sharing a base offset, they behave differently — Hawaii observes no DST, while the Aleutian communities such as Adak do advance to HDT (UTC-9) each summer.
Does Japan observe Daylight Saving Time?
Japan has not observed Daylight Saving Time since 1951, when the practice introduced during the Allied occupation was abolished by the Japanese government. JST has remained fixed at UTC+9:00 ever since, and there is no current legislation to reintroduce DST in Japan.
Is JST the same as Korean Standard Time (KST)?
Yes, South Korea's Korean Standard Time (KST) operates at the same UTC+9:00 offset as JST, and South Korea also does not observe Daylight Saving Time. The two countries share an identical clock year-round, which simplifies scheduling for the significant trade, technology, and cultural exchange between Tokyo and Seoul.