Pick a time, then see it in every zone at once. Rows outside working hours are dimmed so a good meeting slot is easy to spot.
A quick way to convert one moment into many time zones and plan calls that span countries. It uses your browser's own time zone data, so daylight saving is handled automatically. Add each person's city, then nudge the time until every row sits in normal working hours.
The world is divided into time zones offset from Coordinated Universal Time (UTC), roughly one hour per 15 degrees of longitude, so that midday lines up with the sun wherever you are. Converting a time between zones means adding or subtracting the difference in offsets. The tool above converts a time from one place to another, which is essential for scheduling calls, catching live events and coordinating across a distributed team.
Daylight saving is the complication. Many regions shift their clocks forward in spring and back in autumn, and they do it on different dates (or not at all), so the offset between two cities is not fixed year-round. This is why a meeting that was at a convenient hour can drift after a clock change, and why you should convert using the actual date, not a remembered offset.
Scheduling tips. For a call across several zones, quoting the time in UTC removes ambiguity, and it helps to name the zone explicitly ("3pm New York time") rather than assuming. When picking a slot, look for the overlap in everyone's working hours; there is often only a narrow window that suits both a US and an Asian participant, so protect it.