Time Zones & Meetings

Two people describing "3 PM" are not necessarily talking about the same moment, and the offset that converts between them is not fixed year-round in places that observe daylight saving. This category covers converting a specific time between zones, finding a working-hours overlap across a distributed team, planning a meeting that is fair to rotate among time zones, and the daylight-saving edge cases that a naive fixed-offset conversion gets wrong.

An instant and a wall-clock time are different things

"3 PM Tuesday in Chicago" names a specific instant using a local, wall-clock description. Converting it to Tokyo means finding what wall-clock time that same instant is in Tokyo's zone, which requires knowing each zone's actual rules (via its IANA identifier, such asAmerica/Chicago, not a bare UTC offset), because a fixed offset silently breaks the moment either zone crosses a daylight-saving transition.

Some local times are ambiguous, and some do not exist

When clocks fall back, one wall-clock hour happens twice; when they spring forward, one wall-clock hour is skipped entirely and never occurs. A time entered inside either window is flagged rather than silently resolved to a guess, because there genuinely isn't a single correct answer without more information.

Where to go next

For a deadline that needs to be expressed correctly in someone else's local time, see Deadlines & Project Capacity. For a recurring meeting across zones, see Recurrence & Events.