UTC to JST Converter
Japan Standard Time is UTC+9 all year, so add 9 hours to UTC. 00:00 UTC is 9:00 AM in Japan, and 15:00 UTC is 12:00 AM (next day).
UTC to JST Conversion Table
Full 24-hour table. Japan has no daylight saving, so the offset is the same every day of the year.
| UTC (24h) | UTC (12h) | JST (UTC+9) |
|---|---|---|
| 00:00 | 12:00 AM | 9:00 AM |
| 01:00 | 1:00 AM | 10:00 AM |
| 02:00 | 2:00 AM | 11:00 AM |
| 03:00 | 3:00 AM | 12:00 PM |
| 04:00 | 4:00 AM | 1:00 PM |
| 05:00 | 5:00 AM | 2:00 PM |
| 06:00 | 6:00 AM | 3:00 PM |
| 07:00 | 7:00 AM | 4:00 PM |
| 08:00 | 8:00 AM | 5:00 PM |
| 09:00 | 9:00 AM | 6:00 PM |
| 10:00 | 10:00 AM | 7:00 PM |
| 11:00 | 11:00 AM | 8:00 PM |
| 12:00 | 12:00 PM | 9:00 PM |
| 13:00 | 1:00 PM | 10:00 PM |
| 14:00 | 2:00 PM | 11:00 PM |
| 15:00 | 3:00 PM | 12:00 AMnext day |
| 16:00 | 4:00 PM | 1:00 AMnext day |
| 17:00 | 5:00 PM | 2:00 AMnext day |
| 18:00 | 6:00 PM | 3:00 AMnext day |
| 19:00 | 7:00 PM | 4:00 AMnext day |
| 20:00 | 8:00 PM | 5:00 AMnext day |
| 21:00 | 9:00 PM | 6:00 AMnext day |
| 22:00 | 10:00 PM | 7:00 AMnext day |
| 23:00 | 11:00 PM | 8:00 AMnext day |
* From 15:00 UTC onward the Japan time falls on the next calendar day.
Tokyo's Working Day in UTC
Japan's working day starts at 00:00 UTC, so a Tokyo morning is the very start of the UTC date, and the whole working day is over by 08:00 UTC.
| In Japan | JST | UTC |
|---|---|---|
| Office day starts | 9:00 AM | 00:00 |
| Stock exchange opens | 9:00 AM | 00:00 |
| Morning session ends, lunch break | 11:30 AM | 02:30 |
| Afternoon session starts | 12:30 PM | 03:30 |
| Stock exchange closes | 3:30 PM | 06:30 |
| Office day ends | 5:00 PM | 08:00 |
Exchange sessions follow JPX trading hours; the 3:30 PM close dates from November 5, 2024 (it was 3:00 PM before). The 9 AM to 5 PM office day is a planning assumption, not a rule.
Where the Date Changes
Adding 9 hours pushes the later UTC hours onto the next date in Japan. 14:00 UTC is 11:00 PM, but 15:00 UTC is already 12:00 AM (next day), and 23:00 UTC is 8:00 AM (next day). A timestamp written as 23:00 UTC on Monday is a Tuesday morning in Tokyo.
Going the other way, 9:00 AM in Japan is 00:00 UTC the same date, but 8:00 AM in Japan is 23:00 UTC on the previous UTC date, and so is anything before 9:00 AM JST.
No Summer Time in Japan
The offset never changes, and it applies to the whole country, from Hokkaido to Okinawa. Japan did use daylight saving time during the Allied occupation (1948 to 1951 in the tz database) and dropped it after the occupation ended. It has been talked about again several times since, but nothing has been adopted, so software that works with Japan does not need a seasonal rule.
What does change is the other side of the conversion. The gap between Japan and London, New York or Sydney moves with their clock changes: see the time zone converter for the gap on a given date.
Converting a Timestamp in Code
A UTC timestamp ends in Z. The same moment written for JST carries the offset instead: 2026-03-01T15:00:00Z and 2026-03-02T00:00:00+09:00 are one instant, and the local date is a day later. Libraries convert it for you if you give them the zone name Asia/Tokyo instead of a fixed number.
# Python 3.9+
from datetime import datetime
from zoneinfo import ZoneInfo
datetime.fromisoformat("2026-03-01T15:00:00+00:00").astimezone(ZoneInfo("Asia/Tokyo"))// JavaScript
new Date("2026-03-01T15:00:00Z").toLocaleString("en-US", { timeZone: "Asia/Tokyo" })Both give the JST time shown above.