International Meeting Time Planner
Find the hours that suit two or three time zones at once, using the UTC offsets you enter.
Results
Window on your clock
13:00–15:30
Window on their clock
08:00–10:30
Window on the third clock
17:30–20:00
Window in UTC
12:00–14:30
Hours that work for everyone
2.50
h
Is there a time that works for everyone
Yes
What this tool does
Arranging a call across time zones is an intersection problem: each person will take a meeting between certain hours of their own clock, those hours land somewhere different on the UTC line, and the answer is whatever slice all of them have in common. The overlap shrinks fast — Lisbon and New York share a comfortable afternoon, but add Tokyo and you are down to an hour or two at the edges, and some pairs have no civilised overlap at all, which this will tell you plainly. Enter the offsets yourself, in hours, and half-hour zones such as India work as 5.5.
Formula
window in UTC = from the latest (start − offset) to the earliest (end − offset)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
off_a | Your UTC offset | h |
off_b | Their UTC offset | h |
off_c | A third UTC offset | h |
workday_start | Earliest hour anyone will meet | h |
workday_end | Latest hour anyone will meet | h |
WY | Window on your clock | — |
WT | Window on their clock | — |
W3 | Window on the third clock | — |
WU | Window in UTC | — |
HR | Hours that work for everyone | h |
OK | Is there a time that works for everyone | — |
Worked example
- Your UTC offset1 h
- Their UTC offset-4 h
- A third UTC offset5.5 h
- Earliest hour anyone will meet8 h
- Latest hour anyone will meet20 h
- Window on your clock13:00–15:30
- Window on their clock08:00–10:30
- Window on the third clock17:30–20:00
- Window in UTC12:00–14:30
- Hours that work for everyone2.50 h
- Is there a time that works for everyoneYes
Limitations
- Dates are handled as calendar dates. Time zones, daylight saving changes and public holidays are not taken into account.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.