JST to UTC Time Converter
UTC is 9 hours behind JST. JST is UTC+9:00, and UTC is the zero point, UTC±00:00.
Best Time to Call Between JST and UTC
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 4:00 PM to 10:00 PM JST, which is 7:00 AM to 1:00 PM UTC.
both at work JST only UTC only neither — hours along the strip are JST.
Common Times Converted
JST on the left, UTC on the right.
JST to UTC: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| JST | UTC | Working hours |
|---|---|---|
| 12:00 AM | 3:00 PM prev day | UTC only |
| 1:00 AM | 4:00 PM prev day | UTC only |
| 2:00 AM | 5:00 PM prev day | — |
| 3:00 AM | 6:00 PM prev day | — |
| 4:00 AM | 7:00 PM prev day | — |
| 5:00 AM | 8:00 PM prev day | — |
| 6:00 AM | 9:00 PM prev day | — |
| 7:00 AM | 10:00 PM prev day | — |
| 8:00 AM | 11:00 PM prev day | — |
| 9:00 AM | 12:00 AM | JST only |
| 10:00 AM | 1:00 AM | JST only |
| 11:00 AM | 2:00 AM | JST only |
| 12:00 PM | 3:00 AM | JST only |
| 1:00 PM | 4:00 AM | JST only |
| 2:00 PM | 5:00 AM | JST only |
| 3:00 PM | 6:00 AM | JST only |
| 4:00 PM | 7:00 AM | JST only |
| 5:00 PM | 8:00 AM | — |
| 6:00 PM | 9:00 AM | UTC only |
| 7:00 PM | 10:00 AM | UTC only |
| 8:00 PM | 11:00 AM | UTC only |
| 9:00 PM | 12:00 PM | UTC only |
| 10:00 PM | 1:00 PM | UTC only |
| 11:00 PM | 2:00 PM | UTC only |
What JST and UTC Actually Are
JST — Japan Standard Time
Tokyo, Osaka, Yokohama, Nagoya, Sapporo. Standing at UTC+9:00 as written, and the region does not change its clocks, so that offset holds all year. Japan does not observe daylight saving, so this offset is fixed year-round.
Japan abolished daylight saving in 1952 and has resisted every attempt to reintroduce it, including a proposal around the 2020 Olympics.
UTC — Coordinated Universal Time
The global reference standard. Aviation, computing and science run on it. Standing at UTC as written, and the region does not change its clocks, so that offset holds all year.
UTC is not a place. It is a computed standard, kept within a second of mean solar time at Greenwich by atomic clocks, and it is the reference every other zone is defined against.
What This Means in Practice
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.
Major Cities in Each Zone
Cities on JST
Frequently Asked Questions
What is the time difference between JST and UTC?
UTC is 9 hours behind JST.
What is 9:00 AM JST in UTC?
9:00 AM JST is 12:00 AM UTC.
What are the best hours to schedule a call between JST and UTC?
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 4:00 PM to 10:00 PM JST, which is 7:00 AM to 1:00 PM UTC.
Does the difference between JST and UTC change during the year?
No. Neither region changes its clocks, so this gap is fixed all year round.
Does JST always mean Japan Standard Time?
Japan does not observe daylight saving, so this offset is fixed year-round.