Meeting Time-Zone Planner
Find overlapping working hours across multiple time zones.
Overview
The Meeting Time-Zone Planner finds the hours of the day when working schedules overlap across two, three, or more time zones. Add each participant's IANA zone and preferred working window (defaulting to 09:00–17:00 local), and the tool draws a 24-hour grid showing which UTC hours work for everyone, which work for most, and which are off-hours for some attendees.
Useful for distributed engineering teams running standups across continents, customer-success teams scheduling onboarding calls with international clients, conference organisers planning panels with global speakers, and HR coordinators booking interviews between candidates and panels in different countries.
How it works
Each participant's working window is translated to UTC using the IANA tz database (the same data set powering TimeZoneInfo in .NET), accounting for the active DST offset on the specific date you pick. The tool then computes the intersection of all participant windows — those UTC hours that fall inside every local window simultaneously — and reports the result in each participant's local clock.
If no perfect overlap exists, the planner relaxes the constraint and highlights the hour with the maximum partial overlap, useful for asynchronous teams who tolerate one or two attendees being slightly early or late.
Examples
New York (09–17) + London (09–17) + Tokyo (09–17)
→ No three-way overlap; best two-way is 14:00–17:00 UTC (NY morning / London afternoon)
San Francisco (08–18) + Berlin (08–18)
→ Overlap 16:00–17:00 UTC = 09:00–10:00 SF, 18:00–19:00 Berlin
Sydney (09–17) + Bengaluru (09–18) + London (08–17)
→ Overlap 08:00–08:30 UTC (Sydney 18:00–18:30, Bengaluru 13:30–14:00, London 08:00–08:30)
FAQ
Why does my result shift after a DST transition?
When one participant's country springs forward or falls back, their UTC offset moves by an hour and the overlap window shifts accordingly. Pick the actual meeting date, not "today," to get the right answer.
Can I include zones that do not observe DST?
Yes — Asia/Tokyo, UTC, and many other zones are fixed-offset. They contribute the same hours year-round.
How are half-hour and three-quarter offsets handled?
India (+05:30), Nepal (+05:45), and a few Australian states use non-integer offsets. The planner respects them by working in minutes rather than whole hours.
What if there is no overlap?
The tool highlights the closest partial overlap and shows how many participants can attend each hour, so you can choose the least-bad option.
Does it consider weekends?
Working windows are per-weekday. Saturdays and Sundays are excluded by default, which matters when overlap pushes across an international date line.