Meeting planner for time zones
London to Hong Kong
Add up to six cities and move the sun. The light on the planet is real, so daylight saving is already accounted for - and the page says who is at their desk rather than leaving you to count backwards on your fingers.
You move the sun. The world answers.
The globe is not a picture of a globe. The terminator is where the sun actually is at that moment on that date, computed on your own device, so a clock change in one city is a fact of the image rather than a footnote under it. Move the sun or the timeline and every city re-reads - local time, working hours, and whether the whole meeting fits.
Add your cities
Up to six. Set each person's working hours once; Meridian handles the offsets, the daylight saving and the weekend - which is theirs, not ours.
Choose the window
Pick a date and how long the meeting is. The answer accounts for the whole meeting, not just the moment it starts, so a call that would overrun someone's day is not offered as one that fits.
Send it
Copy every local time in one line, add it to your calendar, or share the link - which carries the date, the cities, the time and the length, so they see exactly what you see.
Meridian
London to Hong Kong, hour by hour
Hong Kong is eight hours ahead of London in the British winter and seven in the British summer. Hong Kong has not used daylight saving since 1979, so the gap changes only when the UK’s clocks do.
With 09:00 to 18:00 on both sides, the overlap is London’s first hours and Hong Kong’s last: 09:00 to 11:00 in London in summer, 16:00 to 18:00 in Hong Kong. In winter it narrows to one hour, 09:00 to 10:00 in London and 17:00 to 18:00 in Hong Kong.
For a longer meeting, one side has to move. An 08:00 start in London is 15:00 or 16:00 in Hong Kong depending on the season, and a 19:00 call from Hong Kong is 11:00 or 12:00 in London. Click a city to change its hours and the window redraws.
Questions
Does it handle daylight saving?
Yes. Every time on the page comes from your browser's timezone database, which knows when each city changes. If your call crosses a change, the gap moves and the page shows the new time.
Can I set different working hours for each city?
Yes. Click a city card to edit its hours. Weekends count as out of hours, so the page will tell you nobody is at their desk on a Saturday rather than pretending otherwise.
What if there is no time that works for everyone?
Meridian shows the best fit it can find and names who would be outside hours, rather than pretending it works. The ring is dashed rather than solid when that happens, so a partial answer never looks like a whole one. Widen someone's hours or drop a city and try again.
Can I put Meridian on my own site?
Yes. Choose Embed, copy the snippet, paste it into any page. It carries a small “Built by Digitopia Labs” line, which is the price of it being free.