How to write the time in an invitation
Lead with the time where most of your audience is, then two or three other cities. Use city names, not abbreviations: "New York" is clearer than "EST", which is wrong for most of the year (in summer it's EDT). Put the weekday in, because a 5 PM start in London is the next morning in Sydney, and people check the day first.
A time line that works
Thursday 12 November 5:00 PM London · 12:00 PM New York · 9:00 AM San Francisco (Friday 4:00 AM in Sydney: the recording will be in your inbox)
If one region would have to get up in the night, say so and tell them what they get instead, like a recording, a second session or answers by email. It's more honest than a time line that hides it.
Picking a time for a global audience
There's no time that suits everyone. Some patterns that work:
- Europe and the Americas: late afternoon in the UK is late morning on the US East Coast and early morning on the West Coast. 4 to 5 PM London is a common choice.
- Europe and Asia-Pacific: morning in Europe is afternoon or evening in India, Singapore and Australia.
- The Americas and Asia-Pacific: late afternoon in California is morning the next day in Sydney and Tokyo.
- All three: run it twice, or run it once and send the recording with a way to ask questions.
Daylight saving catches people out
The gap between two cities changes during the year. London and New York are usually five hours apart, but for a few weeks in March and around the end of October, when one has changed its clocks and the other hasn't, they're four. Southern-hemisphere cities change in the opposite direction. That's why this converter works from the date you pick, using the time zone data built into your browser, which comes from the IANA time zone database.
On the registration page and in reminders
Show the time in the reader's own zone wherever you can. In the webinar registrations guide, "when is it in my time zone" is one of the four questions a registration page has to answer fast. A calendar entry does the conversion for them: make one with the add-to-calendar link maker.
In Programmable Talk
Talk stores each event's own time zone and writes dates in it. For an online event, confirmation and reminder emails add the start on the registrant's own clock when their zone is different, for example "9:00 PM", or "Fri 2:00 AM" when it falls on another day. Each registrant also gets a calendar invitation, so their calendar shows it at their local time.