Guide

How to schedule meetings across time zones without anyone joining at the wrong hour

By the AlignHour team at CelaVox · 22 October 2026 · 6 min read

Most cross-time-zone mistakes are not maths mistakes. They happen because a time was written in a way that two people read differently. Here is a routine that removes the guesswork, whether you're booking a client in New York from London or a stand-up with a team in Karachi.

Why meetings across time zones go wrong

• Abbreviations are ambiguous. "EST" is only correct in winter; in summer New York is on EDT. "IST" means India, Ireland or Israel depending on who reads it.
• Countries change their clocks on different dates. The US moves its clocks about two weeks before Europe in spring and one week after Europe in autumn, so for a few weeks a year the gap between them is an hour smaller.
• The date line catches people out. A Monday-morning call in Sydney is still Sunday afternoon in New York.
• Many countries don't change their clocks at all. Pakistan, India, the UAE, the Philippines, Singapore, Japan and Brazil keep the same time all year, so their gap to the US or Europe moves twice a year.

A six-step routine that works

1. Agree whose clock you're planning on. For client calls, plan on the client's clock: "Tuesday 10:00 in New York". It's polite and it's the time they will remember.
2. Write cities, not abbreviations. "10:00 New York (15:00 London)" can't be misread. "10am EST" can.
3. Find the real working-hours overlap. New York and London share about three office hours most of the year (09:00–12:00 New York). London and Karachi share three to four (09:00–12:00 or 13:00 London). New York and Karachi share none, so someone has to start early or stay late.
4. Send the invite from a calendar, with a time zone attached. A calendar invite shows each guest the meeting in their own local time. A time typed into an email does not.
5. Confirm in their time, in words. "See you Tuesday at 10:00 your time" catches most errors before they happen.
6. Double-check during the daylight-saving weeks. Look at every recurring meeting in March, April, October and November. See our 2027 daylight-saving dates.

When there's no good overlap

With more than about eight hours between two places, nobody can meet inside a normal 9-to-5. The fair options are:

• Stretch the day slightly on both sides: an 08:00 start for one person and an 18:00 finish for the other often creates a usable hour.
• Rotate the inconvenient slot for recurring meetings, so the same person isn't always on the call at night.
• Move status updates to writing and keep live calls for decisions.

Check holidays, not just hours

A perfect time on a public holiday is still a no-show. Before you book, check the national holidays in each attendee's country. Religious holidays such as Eid move every year, so don't rely on last year's calendar.