Less time converting.
More time together.
Overlap puts local hours next to each other so you can choose a meeting time without doing time-zone arithmetic.
Start with a date and a few cities
The date belongs to the first city in your list. Each column is one shared moment, displayed in every city’s local time. Add a city by searching its name, or enter a time zone such as Asia/Tokyo. Your city list and working-hour preferences are saved only in this browser.
Find the hours that work
Green blocks mark full hours within each city’s working schedule, initially Monday–Friday, 09:00–17:00. Use Edit working hours to set a same-day window and working days for each city, in 30-minute steps. Apply to save preferences in this browser, or cancel to leave your plan unchanged. Pale blue is other daytime; gray is night, 22:00–07:00. Select any hour, or use Find shared hours to pick the earliest window that fits the duration for everyone. When no shared window exists, the tool favors daytime over night and shows the closest fit.
These are planning preferences, not live availability. Public holidays, lunch breaks, overnight shifts and calendar conflicts are not included. A city with every day unchecked has no working hours. Meetings start on the first city’s whole hour; local times may fall on a half- or quarter-hour.
When another date might work better
Choose Compare nearby dates beneath the planner to search seven dates using the same cities, duration and working hours. The list shows only starts where the whole meeting fits every city’s schedule. Select a start to preview all local dates and times, then use it in the planner; returning without choosing leaves the original plan unchanged.
This comparison uses the planner’s hourly start grid, not every possible half-hour. Dates belong to the first city, and each date uses its own daylight-saving offsets. No results means no full fit on that grid, not proof that everyone is unavailable.
Take the plan with you
Copy the local times into a message, or save an ICS calendar file. The file uses universal time so your calendar can show the meeting in its own time zone. It does not invite guests or connect to any calendar service.
Share a moment, not a calendar
Use Review & share on your selected time to open a meeting page. Recipients see the time in their browser’s time zone and can choose another zone, copy the times or save a calendar file. Adjust a copy in planner opens a separate plan without changing the original link or the recipient’s saved cities or working hours. Working hours carried in the link are used for that copy, not the recipient’s saved preferences; older links use the original weekday 9–5 defaults.
The link carries the plan in the part after #, called a URL fragment. Browsers do not send that fragment to our server. Anyone with the full link can read the cities, time and any working-hour preferences it carries, and the link can appear in browser history or wherever you paste it. Links are snapshots: there are no live updates, RSVPs or invitations.
Daylight saving, without the guesswork
Dates and offsets come from your browser’s time-zone database, including daylight saving changes. The grid shows 24 elapsed hours from midnight in the first city. On a daylight saving transition, a local hour may repeat or be skipped; the end of the grid can spill into the next date. Keep your browser updated for current time-zone rules.
Private plans. Minimal counting.
Your cities, working-hour preferences, meeting date and selected time are processed on your device and are not sent to this server. We do not use cookies, advertising, external fonts, analytics vendors or accounts.
We count page requests and a small set of named actions in aggregate to understand whether this tool is used. Automated traffic and self-checks are filtered where identifiable. A daily rotating, one-way address hash estimates unique visits; we retain only counts, not the hash, raw address, browser string, page query or meeting content. These counts are approximate, not a measure of people.
A public experiment
Overlap is the first product built for socket69.com, an experiment in recurring autonomous software development. The public dashboard shows changes, operations and costs. The product direction can change as we learn.