Convert the time
- Open Time Zone Converter.
- Enter the date and time you have in mind, and the time zone it is in.
- Add the cities of everyone invited and check it is a reasonable hour for each.
Watch out for daylight saving time
Countries change their clocks on different dates, and many never do. The United States moves its clocks in March and November, Europe on the last Sundays of March and October, and much of Asia, Africa and South America not at all. For a few weeks each year, the gap between New York and London is 4 hours instead of 5. Always convert for the actual date of the meeting, not today.
Write the time clearly
- Use a city, not an abbreviation: "15:00 London time" instead of "3 pm GMT", which is wrong half the year.
- Give the time in two or three zones in the invite.
- Use 24-hour time or write am/pm, and include the day of the week, which catches date mix-ups across midnight.
Let the calendar do it
Calendar invites from Google Calendar, Outlook and Apple Calendar store the meeting as an exact moment and show it in each guest's own time zone, as long as the time zone was set correctly when the invite was made.
One meeting, two dates
A meeting at 15:00 London time, on a date in March when only the US has changed its clocks and on a date in April when both have:
| City | Tuesday 17 March 2026 | Wednesday 15 April 2026 |
|---|---|---|
| London | 15:00 | 15:00 |
| New York | 11:00 | 10:00 |
| Los Angeles | 08:00 | 07:00 |
| Mumbai | 20:30 | 19:30 |
| Tokyo | 00:00 Wednesday | 23:00 |
| Sydney | 02:00 Wednesday | 00:00 Thursday |
Every other city shifted against London between the two dates. Most moved by an hour, but Sydney moved by two, because its clocks went back on 5 April.
Finding an hour that works
Some pairs of cities have almost no shared working hours. Between San Francisco and India, 8 to 9 in the morning in San Francisco is 8:30 to 9:30 in the evening in India during US summer time. When there is no fair slot, rotate the meeting time so the same people are not always up late.
Common mistakes
- Half-hour time zones. India is 5½ hours ahead of UTC, Nepal 5¾ and parts of Australia 9½. A meeting on the hour elsewhere starts at half past there.
- Midnight. "Wednesday at midnight" can mean the start or the end of Wednesday. Use 23:59 or 00:00 with the date.
- The southern hemisphere. Australia, New Zealand, Chile and others move their clocks forward in their spring, which is northern autumn, so their gap to Europe changes by two hours over the year.