Why a dial
A day is a circle, so Meridian draws one. Each ring is one person's day in their own time: dark for night, lilac for early mornings and evenings, gold for working hours. The rings are lined up to the same moment, so when everyone is at work you see one lit wedge running through all of them.
Drag the red hand to any time and read off every city's local time underneath. When you've found it, copy one line with the time in every city and paste it into the invite.

Questions
Does it handle daylight saving time?
Yes. Every time is worked out for the date you pick, using your browser's own time zone rules. Pick a date in March or October and the rings move to match, including the odd weeks when Europe and North America change on different Sundays.
Can I set different working hours for each person?
Tap anyone's row to set their hours, rename them or make them the home city. Night shifts that run past midnight work too.
What if there's no time when everyone is at work?
Meridian says so, then finds the closest thing: a stretch when everyone is at least awake, with as many people at work as possible.
How do I send the time to everyone?
Copy times gives you one line with the time in every city, ready to paste into a chat or invite. Add to calendar downloads an invite file, and Share link opens the same dial on someone else's phone.
Do I need an account?
No. Your cities and hours stay on this device. We count page views without cookies.