Meeting planner — find an hour everyone can attend.

Planning a call across time zones

The hard part of a distributed meeting is not converting a time. It is seeing enough of the day at once to notice that the hour which suits one office is 3 a.m. for another. A single converted time hides that; a grid makes it obvious.

1. Add the cities on the call. Pick from the list. Each one adds a row to the grid.
2. Pick a date. The date matters more than people expect, because daylight saving shifts offsets twice a year and not on the same day everywhere.
3. Read down a column, not across a row. A column is one moment in time. The row tells you what that moment looks like in each city, and the colour tells you whether it is reasonable.
4. Pick the greenest column. If no column is fully green, the text below the grid names the least bad option and says which city is paying the price.

When this comes up

• Recurring team calls. A weekly sync needs a slot that is tolerable every week, not just once, which usually means accepting 8 a.m. for one office rather than 11 p.m. for another.
• Interviewing across countries. Candidates will often agree to an unreasonable hour rather than say no. Seeing the whole day makes it possible to avoid asking.
• Scheduling a release or an on-call handover. These have a hard constraint on both ends of the day, and the overlap window is usually narrower than expected.
• Checking a deadline. "Friday end of day" means five different moments depending on who is reading it, and the grid shows exactly how far apart they are.

A worked example: adding a city closes the window

Take a call on 17 November with the organiser in London, and add cities one at a time. Every window below is London time, and every one keeps all cities between 08:00 and 18:00 local:

Two European cities leave ten comfortable hours. Add New York and it halves. Add San Francisco and two hours remain, and those two exist only because London is already at the end of its day while California is starting. Add Singapore and the window disappears entirely: 16:00 in London is midnight there, and going the other way is no better.

This is the pattern that surprises people. The window does not shrink evenly as cities are added, it collapses. A call that felt routine with three cities becomes impossible with five, and negotiation cannot fix it because the constraint is the rotation of the planet.

The grid also shows when the right answer is to split the meeting. Mumbai, Singapore and Tokyo share a window from 08:30 to 15:30 Mumbai time — a normal working day for all three, and 03:00 in London. Two regional calls usually beat one global call that nobody can attend properly.

Where time zone planning goes wrong

• Assuming a fixed offset. London is UTC+0 in winter and UTC+1 in summer; New York is UTC−5 and UTC−4. Two weeks a year the gap between them is four hours instead of five, and that is exactly when the recurring meeting slips.
• Forgetting the half-hour zones. India is UTC+5:30, Nepal UTC+5:45, parts of Australia UTC+9:30. A planner built on whole hours quietly produces wrong times for a large part of the world.
• Ignoring the date line. A call at 9 a.m. in Los Angeles is 1 a.m. the next day in Tokyo, not the same day. Booking systems that only show a time and not a date are how people miss meetings by 24 hours.
• Optimising for the organiser. The person who sends the invite is usually in the most convenient zone by accident. The grid exists to make that visible before it becomes a pattern.

Questions