Time zone calculator
The top strip is your time, the bottom strip is theirs. Drag a strip to a zone, then pick the exact city. The clocks are live and adjust for daylight saving automatically.
They are 1 hour behind you.
When it's 4:45 pm for me in Sydney, it's 3:45 pm for them in Tokyo — they are 1 hour behind you.
How to use it
Each strip shows all 24 hours of the day, coloured so you can see whether a moment falls in the night, the morning, the working day, or the evening. Drag a strip sideways and it glides with your finger, snapping to the nearest zone; the amber box and the two triangles stay locked at the centre. Once a strip lands on a zone, every city in that zone is listed below it — click the one you mean, or type a city into the search box. The clocks then show the real current time, including daylight saving.
How daylight saving is handled
The clocks are computed from each city's real time zone using your browser's built-in calendar, so daylight saving is applied automatically and correctly all year. When New York is on summer time it shows as UTC−4; when it is not, UTC−5 — you do not have to think about it. The drag strip itself is a coarse finder that moves in half-hour steps, so during daylight saving a city can sit a little off the strip's mark; the city clock is always the accurate one. Places that do not observe daylight saving, such as Japan, most of Asia, Queensland and Arizona, simply stay put.
Related questions
Time zone calculator v1.0 — DST engine (May 2026)