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What the calculator shows
A time zone overlap calculator answers one question before you sign with a remote team: how many hours a day can you actually talk? Choose your city and your team's or supplier's city, type both working days, and pick a date. You get the shared hours in both local times, the difference between the two clocks, both days drawn on 24 hours of your own clock, and every day in the next twelve months on which daylight saving changes the overlap.
The tool runs in your browser on the time zone rules your browser already knows, the same database that phones and laptops use. Nothing is sent to us. The address bar keeps your choices, so you can copy the link and send the result to a colleague.
Two things it gets right that a quick mental sum often gets wrong:
- Daylight saving is not simultaneousThe United States moves its clocks on the second Sunday of March and the first Sunday of November, the EU on the last Sunday of March and of October. For a few weeks each spring and autumn the gap between New York and Ghent is five hours instead of six.
- Some places do not switch at all, or switch the other wayPhoenix stays on standard time all year, India and Singapore have no daylight saving, and Sydney's summer is Europe's winter, so the gap between London and Sydney moves twice a year in opposite directions.
Shared office hours between Ghent and the rest of the world
With office hours from 9:00 to 17:00 on both sides, on a typical day outside the switch weeks:
| Your city | Clock against Ghent | Shared hours | The window in your time |
|---|---|---|---|
| London, Dublin | 1 hour behind | 7 | 9:00 to 16:00 |
| Lisbon | 1 hour behind | 7 | 9:00 to 16:00 |
| Amsterdam, Berlin, Paris | same time | 8 | 9:00 to 17:00 |
| Helsinki, Athens | 1 hour ahead | 7 | 10:00 to 17:00 |
| New York, Toronto | 6 hours behind | 2 | 9:00 to 11:00 |
| Chicago, Austin | 7 hours behind | 1 | 9:00 to 10:00 |
| Denver | 8 hours behind | 0 | none |
| Los Angeles, San Francisco | 9 hours behind | 0 | none |
| Dubai | 2 hours ahead in summer, 3 in winter | 6 or 5 | 11:00 to 17:00 in summer |
| Mumbai, Bangalore | 3.5 hours ahead in summer, 4.5 in winter | 4.5 or 3.5 | 12:30 to 17:00 in summer |
The West Coast gets no overlap with a strict 9 to 5 in Europe. Starting at 7:00 in California, which many US teams with European partners do once or twice a week, gives one hour. Ask your supplier which hours they can flex, and put that in the contract rather than in an email.
How much overlap a project needs
No number fits every team. What we see work:
| Overlap | What it supports | How to work |
|---|---|---|
| 6 to 8 hours | working as one team, ad hoc calls, pair programming | as if in the same office |
| 3 to 5 hours | a daily stand-up, same-day answers, reviews in the shared window | the morning or afternoon for talk, the rest for focus |
| 1 to 2 hours | one fixed call a day or a few a week | written tickets, decisions logged, demos recorded |
| none | handover work: one side builds while the other sleeps | a strict written process; slow on unclear questions |
For most custom software, the hard part is not writing code but understanding the business: rules, data from several systems, users who are not technical. That work needs conversation, and the hours above are a reasonable guide to how much of it you can have. More on choosing between close and far teams is in nearshore vs offshore and on nearshore software development.
New York and Ghent: the clock moves four times a year
8 March 2026
The US moves to summer time
New York is 5 hours behind Ghent for three weeks: 3 office hours shared, 9:00 to 12:00 in New York.
29 March 2026
Europe follows
Back to 6 hours: 2 shared office hours, 9:00 to 11:00 in New York, 15:00 to 17:00 in Ghent.
25 October 2026
Europe moves back to winter time
5 hours again for one week, 3 shared hours.
1 November 2026
The US follows
6 hours until March, 2 shared hours.
14 March 2027
US summer time
5 hours, 3 shared hours, for two weeks.
28 March 2027
EU summer time
6 hours, 2 shared hours, until the end of October.
Office hours 9:00 to 17:00 on both sides. The US changes on the second Sunday of March and the first Sunday of November, the EU on the last Sunday of March and of October.
Making a small overlap work
A two-hour window with New York, or one hour with Chicago, is enough for a well-run project if both sides plan for it:
- Fix the call. The same slot every day or every other day, in the overlap, with a short agenda: what was done, what is blocked, what needs a decision.
- Write decisions down. One shared log of decisions with a date and an owner, so nobody waits a day to find out what was agreed.
- Ask questions in writing before your evening. The European team answers them in its morning, before your day starts.
- Show working software. A demo on a test link every second week says more than any status report, and can be watched later.
- Mark the switch weeks. Put the March and October changes from the calculator in both calendars, so the fixed call does not suddenly fall outside someone's day.
This is how we run projects with clients outside Belgium. For a US company the full picture, including contracts, data and costs, is on outsourcing to Europe from the US; for UK buyers, see bespoke software development for UK companies.
Time zones and remote teams
How many hours do New York and Belgium overlap?
Two office hours on most days: 9:00 to 11:00 in New York is 15:00 to 17:00 in Belgium. For about three weeks in March and one in late October or early November the gap is five hours, and the overlap grows to three.
Why does the overlap change in March and October?
Europe and North America switch to and from summer time on different Sundays. Between the two switches the difference is one hour smaller than the rest of the year.
Is the calculator right for India or Australia?
Yes. It uses your browser's time zone database, which includes the half-hour offset of India and the southern hemisphere's opposite summer time in Australia.
Does the tool store what I enter?
No. It calculates in your browser and keeps your choices only in the address bar, so you can share the link.