Timezone Converter & World Clock
Compare current dates and times in Tokyo, New York, London and other cities, with each time difference measured from Tokyo.
Inputs are not collected. Usage measurement requires your consent.
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Timezone Converter & World Clock
Next time, open this tool from My Tools. Only the tool list is saved in this browser, not your inputs or results.
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How to use
- 1
Pick your cities
Start with the default major cities and add more from the list.
- 2
Check the time
The current time and the difference from your base city update in real time.
- 3
Plan ahead
Use it to schedule calls, meetings or travel.
Features
- Real-time clocks for major cities
- Automatic time difference from your base city
- Daylight saving time handled automatically
- Works without location access or server requests
Use cases
Calls and meetings abroad
Check the current time in the other city before scheduling a call or video meeting.
Travel planning
Get a feel for local arrival times and plan your itinerary more easily.
Remote work
Find overlapping working hours when collaborating with teammates overseas.
Details
Time differences exist because regions use different standard times based on longitude. Japan runs on UTC+9, nine hours ahead of Coordinated Universal Time. When scheduling calls or meetings abroad, you need to know the current time and the offset for the other city.
This tool uses the browser's built-in Intl API (Intl.DateTimeFormat), so daylight saving time is reflected automatically - there is no need to calculate offsets by hand. The display updates every second.
Everything runs in your browser: no location access, no server requests. The cities you add are only shown for the current session and are never stored or transmitted.
FAQ
Is daylight saving time reflected?
Yes. The browser's built-in Intl API handles daylight saving automatically, so the local time shown is always accurate.
How often does the clock update?
Every second while the page is open.
What is the time difference between Tokyo and New York?
14 hours in standard time (Tokyo is ahead). During daylight saving it is 13 hours. The tool computes this automatically.
Are the cities I add saved?
No. Added cities are only shown for the current session and are never stored or transmitted.
Related guide
GuideDays Between Dates: Add 30 or 90 Days and Count Both Ends
Calculate days between dates, 30 or 90 days later and inclusive counts. Compare leap years, month ends, and a Japanese public-holiday example.
GuideElapsed Time Calculator Guide: Overnight Hours, Breaks and Multi-Day Work
Calculate elapsed minutes, subtract overlapping breaks once, add hours to a time, and account for daylight saving changes with worked examples.
GuideTime Difference from Tokyo to New York and London: 2027 DST Dates
Calculate time differences from Tokyo using UTC, handle previous and next dates, and verify 2026 and 2027 DST transitions before scheduling a call.
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All processing happens in your browser. Your files are never uploaded.
Verified: Browser tests cover adding and removing cities and clock readings on daylight-saving transition dates
Did you know?
The global time standard is UTC. Japan sits at UTC+9, nine hours ahead.