Scheduling across time zones fails in two predictable ways. Either nobody finds a time that's reasonable for everyone, so someone ends up on a 6 a.m. call every week, or a time is agreed and half the group joins an hour early or late. The first is a geography problem. The second is almost always daylight saving or an ambiguous message.
Step 1: Find the real overlap
Start with each person's working hours in their own time, not yours. "9 to 5" in New York, London and Singapore gives you three eight-hour windows, and you're looking for where they intersect once they're placed on one timeline.
Some pairs overlap comfortably. New York and London share the New York morning, which is London's afternoon. Some pairs barely touch: London and Sydney have no overlap at all within a standard working day for most of the year. Three-city meetings across America, Europe and Asia-Pacific usually have no shared office-hours window, and the honest answer is that someone has to stretch.
The meeting planner lines up up to five cities' working hours and highlights where they overlap, using the offsets for the date you choose.
Step 2: Decide who stretches, and rotate it
When there's no shared window, pick a time that's early for one side and late for another rather than very early for one person and normal for everyone else. For recurring meetings, rotate the inconvenient slot so the same city isn't always on the 7 a.m. or 9 p.m. end. It's a small thing that makes a big difference to whether people keep showing up.
Shoulder hours (8–9 a.m. and 5–6 p.m.) are far more tolerable than anything before 7 or after 9. A slot that falls at lunch in one city is usually fine for a short call but not for a long one.
Step 3: Check the daylight saving weeks
This is the step people skip. Most of North America, Europe and the Southern Hemisphere all observe daylight saving time, but they change on different dates, so the gap between two cities isn't constant through the year.
In 2026, the U.S. moved its clocks forward on 8 March, but the U.K. and the rest of Europe didn't until 29 March. For those three weeks, New York was four hours behind London instead of the usual five. In the autumn, Europe went back on 25 October and the U.S. on 1 November, giving another week at four hours. A recurring 10 a.m. New York meeting moves from 3 p.m. to 2 p.m. in London during those weeks, and the person in London who didn't notice shows up an hour late.
Southern Hemisphere changes run the opposite way. Sydney goes onto daylight time in early October and off it in early April, so the gap between New York and Sydney swings between fourteen and sixteen hours over the year. A 9 a.m. New York call is 11 p.m. in Sydney in July but 1 a.m. the next day in January.
Some places don't change at all: Arizona (outside the Navajo Nation), Hawaii, most of Asia, and much of Africa and South America. Their gap to everyone else changes when the other city changes. The daylight saving guide has the full list of dates.
Step 4: Write the time so it can't be misread
Most no-shows come from the message, not the math. A few habits remove nearly all of the ambiguity:
- Name the city, not the abbreviation. "3 p.m. London time" is clear. "3 p.m. GMT" is wrong for half the year, because London is on BST in summer. "EST" is technically only correct in winter; in summer New York is on EDT. City names avoid the problem completely.
- Give the time in each attendee's zone. "10:00 New York / 15:00 London / 22:00 Singapore" takes a few seconds to write and saves every reader from doing the conversion.
- Include the date, and the weekday, in each zone if it differs. A Monday 7 p.m. call in Los Angeles is Tuesday morning in Tokyo.
- Send a calendar invite. Calendar software stores events in UTC and shows each person their own local time, which is the most reliable way to communicate a time.
Step 5: Let the calendar do recurring meetings, but know what it's anchoring to
A recurring calendar event is pinned to the organiser's time zone. If the organiser is in New York and the meeting is 10 a.m. every Tuesday, it stays at 10 a.m. in New York all year and moves for everyone else when the gaps shift. That's usually what you want, but it's worth saying so in the invite so the people in other cities aren't surprised in March and October.
If the meeting matters more to a city other than the organiser's, set the event's time zone to that city instead.
A quick reference for common pairs
| Cities | Usual gap | Good shared window |
|---|---|---|
| New York – London | 5 h (4 h for a few weeks) | NY 9–12 / London 14–17 |
| New York – Los Angeles | 3 h | NY 12–17 / LA 9–14 |
| London – Dubai | 3–4 h | London 8–13 / Dubai 12–16 |
| London – Singapore | 7–8 h | London 8–10 / Singapore 16–17 |
| Los Angeles – Tokyo | 16–17 h | LA 16–18 / Tokyo 9–10 next day |
The shared windows are approximate, based on a 9-to-5 day at each end, and shift by an hour during daylight saving changes. For a specific date, the meeting planner is more reliable than any table.