About the project

Built for teams that
live in different clocks

Overlap is a free visual timezone grid. Add up to 10 cities, drag the slider, and find the green zone where everyone is awake. No signup, no account, no tracking — just instant clarity.

Every remote team goes through the same ritual. Someone opens a timezone converter, types a city, gets a time, opens a new tab, types another city, does mental arithmetic, makes a mistake, starts over. For 10 cities it takes 5 minutes and still feels uncertain.

Standard timezone tools are built for converting one time between two places. They're not built for the actual question remote teams ask: "When is everyone awake at the same time?"

Overlap is built for that question. You see all cities simultaneously, coloured by status, and the answer is visual — green columns are where everyone overlaps. No arithmetic. No tabs. No mistakes.

140+
Cities included
10
Max cities at once
0
KB of external JS
$0
Cost to use, forever

Overlap is a single HTML file with no external JavaScript dependencies. All timezone logic uses the browser's native Intl.DateTimeFormat API, which handles daylight saving time, UTC offsets, and locale-specific formatting automatically.

Frontend
Pure HTML, CSS, vanilla JS. Zero frameworks, zero build step.
Timezone data
Intl.DateTimeFormat — native browser API, no library needed.
Hosting
Cloudflare Pages — global CDN, 200+ edge nodes, unlimited traffic.
Analytics
Privacy-first, no cookies, no fingerprinting.

Overlap is intentionally a single-purpose tool. It does one thing well: shows a 24-hour colour grid so you can find when your global team overlaps. It will never require a login for core features, never sell your data, and never add complexity that gets in the way of that one job.

The entire application is a single HTML file you can download, inspect, and run locally forever. No lock-in. No servers to break. No accounts to delete if you want to leave.

If you find it useful, buying a coffee keeps the domain registered and the lights on.

Ready to find the green zone?

Open the app and add your cities. It takes 30 seconds.

◎ Open the app ☕ Support