World Clock
Four clocks side by side, each on its own UTC offset, ticking together with UTC itself.
Results
What this tool does
Working across time zones is mostly a matter of not having to do the arithmetic every time somebody suggests a slot. Set the four offsets you actually deal with — your own, the office abroad, the client, the supplier — and the four clocks run together, with UTC shown as the common reference. Half-hour and quarter-hour offsets work: India is +5:30, Nepal +5:45 and Chatham Island +12:45.
Formula
hour local = hour UTC + time zone deviation
Variables
| Symbol | Meaning | Unit |
|---|---|---|
offset_1 | First offset from UTC | h |
offset_2 | Second offset from UTC | h |
offset_3 | Third offset from UTC | h |
offset_4 | Fourth offset from UTC | h |
utc_ms | Current moment | — |
T1 | First clock | — |
T2 | Second clock | — |
T3 | Third clock | — |
T4 | Fourth clock | — |
UT | UTC | — |
Worked example
- First offset from UTC0 h
- Second offset from UTC1 h
- Third offset from UTC-5 h
- Fourth offset from UTC9 h
- Current moment50,400,000
- First clock14:00
- Second clock15:00
- Third clock09:00
- Fourth clock23:00
- UTC14:00
Limitations
- The calculation runs entirely in your browser. The values you type are never sent to a server.
- Dates are handled as calendar dates. Time zones, daylight saving changes and public holidays are not taken into account.
Frequently asked questions
Why type the offsets instead of picking cities?
Because a city does not have one offset, it has two — one for winter and one for summer — and the dates they change on differ by country and get altered by governments with little notice. A list of cities would be quietly wrong twice a year. Typing the offset that applies on the day you care about is the only version that cannot go stale, and it handles the half-hour and quarter-hour zones without a special case.