Time Zone Overlap Finder

Time zone overlap: how it works

Start by subtracting the two UTC offsets to get the gap between the zones, then slide one side's working hours across to see where they fall on the other clock. Take a concrete case. Example: São Paulo (UTC−3) and New York (UTC−5) are 2 hours apart, so SP's 9:00–12:00 window lands at 11:00–14:00 in NY, right over lunch. SP (UTC−3) against London (UTC+0) is trickier: 4 hours in winter, 3 in summer, since the UK runs BST (British Summer Time) and Brazil dropped DST back in 2019.

Applications

It comes in handy when you're scheduling international meetings, planning shifts for remote work across continents, sizing a follow-the-sun 24/7 customer support rotation, or coordinating multi-region engineering teams. Two zones less than 5 hours apart usually give you 3–4 hours of practical overlap. Once the gap passes 8 hours, lean on async and rotate the meeting time so everyone takes a turn with the awkward slot.

FAQ

Does daylight saving time affect the calculation? It does. DST moves the offset by 1 hour. The U.S. starts on the second Sunday in March and the EU on the last Sunday in March. Brazil no longer observes it at all.

What's a good window for global meetings? 09:00–11:00 UTC usually catches the Americas, Europe and parts of Asia at the same time.

How do I handle teams more than 12 hours apart? Make async the default and cap live meetings at 1–2 a week, rotating who has to sit through the inconvenient hour.