How to Find Shared Work Hours Across Time Zones
I used to do this manually: open worldtimebuddy, squint at tiny timezone blocks, try to find where the colors aligned. Then I'd forget what I found and do it again next week. At some point I just built a tool to make it obvious.
The Basic Problem
If your team is in two timezones, you probably already know the overlap. But add a third, or a fourth, and it gets messy fast.
Here's the math that always surprises people: a 9-to-6 worker in New York (Eastern Time, UTC-5 in winter) and a 9-to-6 worker in London (GMT, UTC+0) only share four hours of overlap. London 2pm-6pm is New York 9am-1pm.
That 4-hour window is if both teams actually work 9-to-6 in their local time. When you factor in commutes, lunch breaks, school runs—real life—the actual usable overlap is usually smaller.
Start With Boundaries
Before hunting for perfect times, figure out what's completely off-limits. Late night for everyone? Early morning for your Asia team talking to Americas? These "no-go" zones narrow the search space fast.
Also think about recurring problems: Friday evenings, weekends, major holidays in any team's location. A meeting scheduled during someone's kid's bedtime isn't going to go well.
The Tool Approach
Manual calculation works for two timezones, maybe three. Past that, you're just guessing.
The Team Timezone Coordinator shows you overlap as a heatmap. Green means everyone's in working hours. Yellow means some people are outside their window. Red means someone's being asked to attend outside normal hours.
It's not complicated, but having the visual makes it easier to have the "we have a problem here" conversation with your team.
Some Rules I've Learned
Rotate the pain. If Tokyo took the late call this week, they get a pass next week. Same people shouldn't always sacrifice.
Document the timezone explicitly. "3pm" means nothing when half your team is in Europe. Write "3pm JST / 10pm PST" and nobody has to guess.
Default to async. Not every decision needs a meeting. If you can write it in a doc and get comments asynchronously, you've removed a whole category of timezone problems.
When You Have to Meet
If you must schedule outside everyone's ideal window: announce it well in advance, explain why it's necessary, acknowledge the inconvenience, and make it rare. The process doesn't prevent exceptions but ensures they stay exceptional rather than becoming the new normal.
The goal is sustainable collaboration. Perfect overlap across time zones is mathematically impossible for most teams. What's possible is fairness—somebody always being asked to sacrifice isn't fairness, it's a broken system.