Why Overlap Matters
The rise of remote work means teammates might log in from opposite sides of the world. While asynchronous communication tools are essential, many tasks still benefit from real-time discussions. Knowing how many hours of overlap you share with a colleague helps you plan meetings and live collaboration sessions without constant late-night scheduling. This calculator provides a quick number you can reference when planning your week.
The Overlap Formula
To find the overlap between two work schedules, take the later of the two start times and subtract it from the earlier of the two end times. The MathML representation for members A and B is shown below:
Here and are the start and end times for member A, while and refer to member B. If the result is negative, that means there is no overlap in their schedules, and the function clips it to zero.
Example Table of Time Zones
The table below lists common time zones and their offsets from Coordinated Universal Time (UTC). It can help you convert member hours from local time to a common reference.
| Region | UTC Offset |
|---|---|
| New York (EST) | -5 |
| London (GMT) | 0 |
| Berlin (CET) | +1 |
| Bangalore (IST) | +5.5 |
| Sydney (AEST) | +10 |
Putting It In Context
If member A works from 9:00 to 17:00 in New York and member B works from 9:00 to 17:00 in Berlin, convert both to UTC. Member A spans 14:00 to 22:00 UTC, while member B spans 8:00 to 16:00 UTC. The overlap is from 14:00 to 16:00 UTC—just two hours for meetings. Use this calculation whenever new teammates join or schedules shift throughout the year.
Scheduling Strategies
Even with only a small overlap window, planning ahead makes it easier to coordinate. Rotate meeting times so one person doesn\'t always bear the brunt of late or early hours. Document decisions in shared notes and record sessions if participants occasionally miss them. Overlap calculators like this one keep scheduling fair and transparent.
Async Collaboration Tips
Once you know how few overlapping hours you have, it\'s important to invest in asynchronous workflows. Shared project boards, clear documentation, and recorded video walkthroughs help bridge the time gap. When a teammate wakes up in a different timezone, they can quickly catch up on what happened while they were offline. This keeps progress steady even if overlap is just a couple of hours per day.
Expanding the Team
As teams grow, the complexity increases. If you have members in three or more zones, you can extend the formula to calculate pairwise overlap for each set of collaborators or look for a single time block when everyone is online. Some companies split into smaller pods to keep coordination practical. Understanding overlap is the first step in designing a schedule that balances responsiveness with respect for personal time.
Remote Culture Considerations
Cultural norms around working hours differ globally. In some regions, a late-afternoon meeting might intrude on the dinner hour, while in others it\'s expected. Communicate preferences openly so you can adjust overlap expectations. Setting clear boundaries around availability—especially outside standard hours—prevents burnout and fosters trust.
Using This Tool
Enter each member\'s start and end times in their own local hours after you\'ve converted to a common timezone. The result displays the hours available for real-time collaboration. Experiment with shifting one schedule by an hour or two to see how overlap changes. For bigger teams, repeat the calculation for each pair or adapt the concept to find the maximum shared block.
Although the math is simple, visually seeing the overlap helps when pitching schedule adjustments to management or clients. It\'s easier to justify asynchronous communication when you can show the limited window for live chats.