Time zone etiquette for scheduling international meetings.
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Write every meeting time with its zone and in the other person's zone too, use city names instead of abbreviations, and check the few weeks a year when daylight saving makes the gap shift by an hour. Offer options in the recipient's morning, rotate who adapts, and confirm 24 hours before.
Write the time in their zone as well as yours.
Most scheduling mistakes happen in the text of an e-mail, not in the calendar. A time with no zone is a guess, and a time in your zone only makes the other person do the sum. Put both in the sentence: '10:30 Barcelona, 17:30 Singapore'. If you have a group, list each zone once, in order from east to west.
- Included: Write the date as well as the time, with the weekday: 'Tuesday 9 March, 10:30 Barcelona, 17:30 Singapore'. The weekday catches a date that has slipped across midnight.
- Included: Use the 24 hour clock. '5:30' is ambiguous across a call between two countries.
- Included: If the date is different in the other zone, say so: '08:00 Sydney, Wednesday'.
- Included: Give a duration, not only a start time: '30 minutes'.
Use city names, not abbreviations.
Abbreviations look precise and are not. 'CST' can mean Central Standard Time in North America, China Standard Time or Cuba Standard Time. 'IST' can mean India, Israel or Ireland. 'BST' is British Summer Time to a Londoner and Bangladesh Standard Time to someone in Dhaka. Even 'CET' is wrong for much of the year, because central Europe is on CEST from late March to late October.
Write the city instead: 'Barcelona', 'New York', 'Sydney'. A city carries its daylight saving rules with it. In software, the standard names come from the IANA time zone database and look like Europe/Madrid or America/New_York. Use those in any system, invitation or spreadsheet that has to calculate the time, and city names in anything a person reads.
Know the weeks when the gap changes.
Regions change their clocks on different dates, so for a few weeks each year the gap between two cities moves by one hour. In the EU and the UK the clocks change on the last Sunday of March and the last Sunday of October. In the United States they change on the second Sunday of March and the first Sunday of November. New South Wales, which includes Sydney, and several other Australian states change on the first Sunday of April and the first Sunday of October. Singapore does not change its clocks at all.
In 2027 that gives the following dates, worked out from those rules. Check them each year, because governments can change the rules.
| City pair | Gap in hours | Dates in 2027 |
|---|---|---|
| London and New York | 5 | 1 January to 13 March, 28 March to 30 October, 7 November to 31 December |
| London and New York | 4 | 14 to 27 March, 31 October to 6 November |
| Madrid and New York | 6 | The same dates as London and New York |
| Madrid and New York | 5 | 14 to 27 March, 31 October to 6 November |
| London and Singapore | 8 | 1 January to 27 March, 31 October to 31 December |
| London and Singapore | 7 | 28 March to 30 October |
| London and Sydney | 11 | 1 January to 27 March, 31 October to 31 December |
| London and Sydney | 10 | 28 March to 3 April, 3 to 30 October |
| London and Sydney | 9 | 4 April to 2 October |
Here is the trap. A recurring call at 15:00 London time is 10:00 in New York for most of the year, and 11:00 in New York from 14 to 27 March. Someone who set up the call in February will find it an hour late in March, and wrongly blame the other side. Put the weeks in your diary and send a reminder with both times the week before each change.
Find the overlap before you propose a time.
Take 09:00 to 17:00 as the working day in each city and see what is left. The figures below are for the summer months, from April to September, when the gap between Europe and Sydney is smallest.
| City pair | Shared hours | Where to look |
|---|---|---|
| London and New York | 3 | 14:00 to 17:00 in London, 09:00 to 12:00 in New York |
| London and Singapore | 1 | 09:00 to 10:00 in London, 16:00 to 17:00 in Singapore. None in winter |
| London and Sydney | 0 | Stretch one side: 08:00 in London is 17:00 in Sydney |
| New York and Singapore | 0 | 21:00 in New York is 09:00 the next day in Singapore |
| New York and Sydney | 0 | 19:00 in New York is 09:00 the next day in Sydney |
| Singapore and Sydney | 6 | 11:00 to 17:00 in Sydney, 09:00 to 15:00 in Singapore. 5 hours from October to March |
When there is no overlap, the meeting is an early start or a late finish for somebody. That is fine once in a while, as long as you decide who it falls on.
Rotate the inconvenience.
If the same side always takes the 07:30 call or the 21:00 call, they will notice. Alternate: this month you take the early start, next month they do. Say it out loud ('We took the late one last time, so this one is in your morning') and it reads as courtesy rather than a favour.
- Included: Offer two or three options, all in the recipient's morning if you can.
- Included: State your own constraints first: 'I can do Tuesday or Thursday between 14:00 and 16:00 London.'
- Included: Never schedule a meeting before 07:00 or after 20:00 in someone's own zone without asking.
Send an invite, and treat the text as the risk.
A calendar invitation stores one exact moment and each calendar shows it in its owner's zone. That is why an invite is safer than a line of text. The risk is the e-mail around it. If the body says 10:30 and the invite says 10:30 in a different zone, the two disagree and people trust the text. Copy the time from the invite into the message, with both zones, and send them together.
At a trade show, the clock belongs to the venue.
A stand meeting happens in the venue's time, whoever books it. If your stand is in Barcelona, 10:30 means 10:30 Barcelona to everyone, including the visitor who booked from Tokyo before flying. Write the venue's time first, then the visitor's. A visitor from another continent should book in their own time, because they are the one converting. Phone and video calls before or after the show run in the rep's zone, with the visitor's zone shown beside it. Exhibitors set the venue's zone once per show, as described on 1Namecard for exhibitors.
Align your team too. If your reps travel from different countries, agree on one clock for the roster, and use the venue's. The booth staffing schedule is easiest to follow when every shift is written in venue time.
Confirm 24 hours before, and plan for no-shows.
Send a short confirmation 24 hours ahead with both times, the link or the stand number, and a line that says how to move it. Most time zone errors surface here, while there is still time to fix them. If someone does not arrive, wait 10 minutes, send one friendly message with both times, and offer two new options. Do not assume rudeness: check the time you wrote first. A missed meeting at a show is still a warm contact, so follow it up as described in how to capture and follow up trade show leads.
Check the calendar for public holidays and weekends before you propose a date. Not every country rests on Saturday and Sunday. Saudi Arabia, for example, has a Friday and Saturday weekend. The United Arab Emirates moved its federal government to a Saturday and Sunday weekend, with a shorter Friday, from 1 January 2022, while private employers choose their own rest day. Holidays that follow a lunar calendar, such as Eid and Lunar New Year, move from year to year.
- Step 1.
Write the date with the weekday, the 24 hour time and the duration.
- Step 2.
Name both cities, never an abbreviation.
- Step 3.
Check the daylight saving weeks for both places.
- Step 4.
Offer two or three options in the recipient's morning.
- Step 5.
Send an invite and copy its time into the message.
- Step 6.
Confirm 24 hours before with both times.
- Step 7.
Check holidays and the local weekend.
Quick answers.
How do you write a meeting time for people in two time zones?
Write the weekday, the date, the time in 24 hour format and the city for each zone, for example Tuesday 9 March, 10:30 Barcelona, 17:30 Singapore. Add the duration. Use city names rather than abbreviations such as CST or IST, which each mean more than one zone.
When do the clocks change in 2027?
In the United States the clocks go forward on Sunday 14 March and back on Sunday 7 November. In the EU and the UK they go forward on Sunday 28 March and back on Sunday 31 October. New South Wales goes back on Sunday 4 April and forward on Sunday 3 October. Singapore does not change its clocks.
Who should take the inconvenient time in an international meeting?
Take turns. If one side always takes the early or late slot, say so and swap next time. Offer options in the recipient's morning where you can, and avoid anything before 07:00 or after 20:00 in their zone unless they agree.
Does a calendar invite handle time zones for me?
An invite stores one exact moment, and each calendar shows it in the owner's zone, so it is safer than text. Mistakes usually come from the message around it. Copy the time from the invite into the e-mail with both zones, and confirm 24 hours before.