Meeting Time Overlap Finder

Add 2–6 participants — each with a time zone, a working window, an optional lunch break, and a set of working days — and see when everyone is simultaneously in their working hours. The 7×24 heatmap below shows every UTC hour of the working week, colour-coded by how many people are available. Click any cell to see each participant's local time and reason for being unavailable. Pure client-side, offline.

Participants

Defaults to a 9–17 Mon–Fri schedule with no lunch break. Toggle a day off by clicking the chip. Type any 09:30–17:00 time, or 17:30 for half-hour windows. The available time zones are the same 47 curated IANA zones used by the Time Zone Converter.

Best time to meet — —

Best window length —

Any-overlap cells —

Full-overlap cells —

Weekly heatmap (UTC)

Each cell is one UTC hour. Hover or click a cell to see the per-participant local times. Cells are coloured from nobody available to everyone.

Click any cell to see who is in their working window.

Top 3 windows

The longest three contiguous runs of cells at the highest attendance level. Times are in UTC; click a row to see the matching cells highlighted on the heatmap.

How the math works

For every UTC hour of the working week, the page looks up each participant's local time in their zone using Intl.DateTimeFormat — the same engine your browser uses for every date display. A participant is available when the local wall-clock is inside their working window, outside their lunch block, and on a working day. The cell's count is the number of available participants. The "best" window is the longest contiguous run of cells at the maximum count. Daylight Saving is handled cell-by-cell: a participant whose local time crosses a DST boundary in the anchor week will see their availability shift accordingly, just like they would in real life.

We deliberately do not model public holidays, vacation blocks, minimum-attendance thresholds, or pre-meeting prep time — keep the scope tight to "when is everyone in their working hours, accounting for lunch". Use the per-cell detail view to investigate edge cases (e.g. a participant whose working day crosses midnight in UTC, which is rare but real for some Asia / Pacific teams).