Compare JST vs BST
See the current time difference between Japan Standard Time and British Summer Time, including DST effects and the best hours to meet.
How to Find the Time Difference Between JST and BST
Open the JST vs BST converter: Go to https://www.xconvert.com/time-converter/jst-vs-bst to open the comparison grid with Japan Standard Time (JST) and British Summer Time (BST) already loaded. This page is useful when you are scheduling a call between Tokyo and London, planning support coverage between a Japan-based product team and a UK sales office, or checking whether a same-day handoff is realistic.
Add comparison cities relevant to your workflow: Click + Add City and add cities such as Tokyo, London, New York, or Singapore depending on your use case. For example, finance teams often compare London with Tokyo because both are major global financial centers, while multinational tech teams may also add New York to see whether a three-region meeting can fit inside normal work hours.
Drag across the grid to select a meeting window: Click Select if needed, then drag across the colored timeline on the JST row to highlight a time range in purple; you can resize it with the left and right handles or move it by dragging the center. For example, if you drag 3:00 PM to 5:00 PM JST, the BST row will show 7:00 AM to 9:00 AM BST on the same day, which is often workable for a London morning call but too early for teams that start after 9 AM.
Export and share the selected overlap: Once a range is selected, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This is especially useful if a Tokyo engineering manager wants to send a confirmed handoff slot to a London operations team so each participant sees the meeting in local time without manually converting UTC offsets.
JST vs BST Offset Explained
JST is 8 hours ahead of BST. Japan Standard Time is fixed at UTC+9 all year, while British Summer Time is UTC+1 during the UK's daylight saving period. That means when it is 9:00 AM in London on BST, it is 5:00 PM in Tokyo on JST, and when it is 6:00 PM in Tokyo, it is 10:00 AM in London.
The seasonal detail matters because BST is not used all year. In the United Kingdom, clocks move forward from Greenwich Mean Time (GMT, UTC+0) to British Summer Time (BST, UTC+1) on the last Sunday in March, and they move back on the last Sunday in October. During the BST period, the Japan–UK time difference is 8 hours; outside that period, when the UK is on GMT, JST is 9 hours ahead of the UK.
For a concrete example, in summer, a Tokyo team working 10:00 AM to 6:00 PM JST overlaps with London roughly from 2:00 AM to 10:00 AM BST, leaving only a narrow practical collaboration window in the Tokyo late afternoon / London early morning. In winter, that overlap shifts by another hour, so 5:00 PM JST becomes 8:00 AM GMT instead of 9:00 AM BST, which can slightly improve early-day coordination for UK teams.
This difference is important for industries that connect Japan and the UK regularly. Financial services, automotive manufacturing, gaming, logistics, and multinational technology companies often coordinate between Tokyo and London because both cities are major business hubs: Tokyo metropolitan area has roughly 37 million people, while London metropolitan area has around 14 million people depending on the boundary used. Teams handling cross-border trading, product launches, customer support escalations, or air cargo scheduling often use the JST–BST comparison to avoid missed handoffs caused by daylight saving changes in the UK.
A practical scheduling rule is that Tokyo afternoon usually matches London morning during BST. For example, 4:00 PM JST = 8:00 AM BST, 6:00 PM JST = 10:00 AM BST, and 8:00 PM JST = 12:00 PM BST. This makes Tokyo late afternoon to early evening one of the most realistic windows for live meetings, while London afternoon usually pushes Tokyo into late night or the next calendar day.
Frequently Asked Questions
What is the exact time difference between JST and BST?
The exact difference is 8 hours, with JST ahead of BST. Japan Standard Time is UTC+9 and British Summer Time is UTC+1, so you subtract 8 hours from Tokyo time to get London summer time. For example, 1:00 PM JST = 5:00 AM BST, and 9:00 AM BST = 5:00 PM JST.
Is JST always 8 hours ahead of the UK?
No, JST is 8 hours ahead only when the UK is observing BST, which runs from the last Sunday in March to the last Sunday in October. During the rest of the year, the UK uses GMT (UTC+0), so JST becomes 9 hours ahead instead. This is why recurring meetings between Japan and the UK often need to be adjusted twice a year.
Does Japan use daylight saving time?
No, Japan does not currently observe daylight saving time, so JST stays at UTC+9 throughout the entire year. That makes Japan easier to schedule around because the offset only changes when the other country changes clocks. In the JST vs BST comparison, all seasonal movement comes from the UK side, not from Japan.
What time works best for meetings between Tokyo and London during BST?
The most practical meeting window is usually Tokyo late afternoon to early evening, which corresponds to London early morning to late morning. For example, 5:00 PM JST = 9:00 AM BST and 7:00 PM JST = 11:00 AM BST, which works well for project check-ins, sales updates, and operations handoffs. If London schedules calls after 2:00 PM BST, Tokyo participants are already at 10:00 PM JST, which is usually too late for daily collaboration.
How does the time difference affect business between Japan and the UK?
The 8-hour gap during BST creates a limited same-day overlap, so many companies rely on carefully timed standups, written handoffs, and calendar invites with automatic timezone conversion. This is especially relevant for banks, insurers, shipping firms, automotive groups, media companies, and software teams operating between London and Tokyo. A meeting scheduled for 8:30 AM BST reaches Tokyo at 4:30 PM JST, which is often ideal for end-of-day review in Japan and start-of-day planning in the UK.
Why does the JST vs BST difference change later in the year?
It changes because BST is a seasonal daylight saving time, not the UK's permanent year-round clock. When the UK leaves BST on the last Sunday in October, it returns to GMT, increasing the difference from 8 hours to 9 hours. If you keep a recurring meeting at the same local clock time in London, the Tokyo time will shift by one hour after that transition.
How can I check a JST to BST meeting visually instead of converting manually?
Use the grid on the JST vs BST page and drag directly across the JST or BST timeline to see the corresponding hours in both zones at once. The color-coded rows help you spot whether your selected time falls in normal work hours, evening, or night, which is more useful than doing raw UTC math when planning real meetings. This is particularly helpful for remote teams deciding whether a release review at 6:00 PM JST is acceptable for a London stakeholder, since the tool immediately shows that it is 10:00 AM BST.