Finding working-hour overlap across time zones
How to line up a meeting that lands inside everyone's workday, why UTC offsets shift with the seasons, and how to read a world clock table.
Why a shared instant looks different everywhere
A meeting happens at one moment in time, but every participant experiences it on their own wall clock. When it is 16:00 in London it is 11:00 in New York and already past midnight in Tokyo, because each zone sits at a fixed offset from UTC. The planner takes the single instant you choose and formats it in each zone, so instead of doing offset arithmetic in your head you read the actual local time and date straight from the table. That removes the classic mistake of adding hours in the wrong direction.
Working-hour overlap is the real constraint
The hard part of global scheduling is not the time difference itself but the shrinking window where everyone is awake and at work. With a 9am to 5pm workday, teams in the US and Europe share only a few afternoon-in-Europe, morning-in-America hours, and adding an Asia-Pacific colleague can erase the overlap entirely. The In hours and Off hours tags let you see at a glance whether a proposed slot sits inside each person's day, so you can trade a slightly early or late hour for one city instead of guessing.
Daylight saving keeps offsets moving
Offsets are not constant. Most of North America and Europe shift their clocks forward in spring and back in autumn, and the southern hemisphere does the opposite, so the gap between two cities can change by an hour twice a year. The transition dates do not even line up between countries, which creates short windows where the usual difference is off by an hour. Because the planner reads the offset from the exact instant you pick rather than from a fixed table, it always reflects whichever daylight saving rule is in force on that date.
Turning the table into an invite
Once a slot works, the goal is to communicate it without ambiguity. Listing each attendee's local time and date, as the Copy summary does, is clearer than naming a single zone and trusting everyone to convert it. Including the UTC offset removes any doubt about which version of a zone you mean, and calling out the city that is a day ahead or behind prevents someone from joining twenty-four hours off. Pasting that summary into the invite gives every reader a line they can trust at a glance.