The meeting-time problem, and how Overlap solves it
Overlap is a free board that lays several people's days on one line, so you can see — not calculate — the hour that works for all of them.
Scheduling across time zones is not really arithmetic. Everyone can add and subtract hours. What people get wrong is the human part: 08:00 in Berlin is an ordinary hour for a Berliner and a cruel one for someone in Los Angeles, and nobody notices until the invite has already landed.
Overlap puts both days on the screen at once. Each person becomes a horizontal band of their own local day — asleep, awake, at work — and the columns where the bands agree are the hours a meeting can actually happen. The awkwardness is visible before you send anything.
What it does
Add a person by city, by IANA time zone, or by a raw offset like UTC+3. Each one gets a row: a 24-hour band of their local day, marked grey while they are asleep, amber while they are awake but off the clock, and green inside their working hours.
Working hours are per person, not global. The default is 09:00–18:00 local time and you change it on the row itself. A developer who starts at 11:00 and a client who stops at 16:00 both keep their real day, and the board answers accordingly.
Below the board, Overlap ranks one-hour windows: how many people are inside working hours, how many are merely awake, and — when nobody can have it easy — exactly who has to bend. You get a sentence in plain language, not a colour puzzle to decode.
Every board lives in its own link. Copy it and the person who opens it sees the same people, the same names, the same working hours, the same date and the same anchor — in their own reading of the clock.
Why the usual methods fail
Mental math is fine for two cities you know well. It falls apart at four cities you don't, and it breaks entirely the week one country changes its clocks and the other has not yet.
A world clock tells you what time it is somewhere. It does not tell you whether that person is asleep, eating dinner, or three hours into their working day — which is the only thing you needed to know.
A scheduling poll asks everybody else to do the conversion for you. That is precisely the work you were trying to avoid, and now nothing can be booked until the slowest person replies.
A calendar's built-in “find a time” works beautifully inside one company on one calendar system. It knows nothing about the contractor, the client, or the candidate you are trying to meet.
How it works
Offsets and daylight-saving rules come from the browser's own IANA time zone database through the standard Intl API. There is no offset table to go stale: if the browser knows about a rule change, so does the board.
Daylight saving is resolved per person and per date, not once for the whole board. Pick a date in late March or late October and watch the bands slide: a spring-forward day is drawn with 46 half-hour columns and a fall-back day with 50, because that is how long those days really are.
Columns are half an hour wide, so zones at :30 and :45 — India, Nepal, Chatham Islands — line up honestly instead of being rounded to the nearest hour.
The board is drawn along one person's calendar day, the anchor, and you choose whose. That matters when a window falls after midnight for somebody: the row shows “next day” rather than quietly wrapping around.
Windows are scored, not guessed. Being at work counts fully, being awake near working hours counts partly, being asleep disqualifies the window outright. Candidates are kept at least two hours apart so the three suggestions are genuinely different options, and each person gets an early / late / off-hours flag.
Any window exports to a calendar file. The event description carries everyone's local start time and a link back to the board, so the people you invite can check the reasoning themselves.
For a recurring call with no comfortable hour, there is a fair rotation: shift the awkward window week by week so the same person is not always the one taking the call at 22:00.
Nothing is stored on a server. There is no account, no cookie for tracking, and no record of who you meet with — the board is encoded in the URL and the city index is a static file your browser downloads once. Saved teams live in your own browser's storage and never leave the device.
Five situations it was built for
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The distributed standup
A team across three continents needs one recurring half hour. Overlap shows whether a window inside everyone's working hours exists at all — and when it doesn't, which person is paying for it, so you can rotate the cost instead of pretending it is free.
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Interviewing across borders
A candidate two continents away reads the hour you propose as a signal about the company. Set their city, look at the green columns, and offer a time that does not ask them to perform at 22:00 on a work night.
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Client and agency calls
You rarely know a new client's real working day. Set their city and hours once, send them the board, and let them counter-propose by looking at the same picture instead of trading “does 3 p.m. your time work?” messages for two days.
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Contract work in two markets
One contract in Berlin, another in Singapore. Put both on the board with your own row in the middle and you can see — before you promise anything — how many hours of genuine overlap you actually have each day.
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Family and friends abroad
The grey band is the useful one here. It tells you when a call would wake someone up, and the amber band tells you when they are up but would rather be having dinner.
Questions people ask
Do I need an account?
No. There is nothing to sign up for and nothing to install. Open the page, add people, send the link.
Where is my data stored?
Nowhere on our side. The people you add are encoded in the URL in your address bar, and all the time zone work happens inside your browser. Saved teams use your browser's local storage and stay on that device.
Does it handle daylight saving time?
Yes, per person and per date. Change the date to a transition day and the board itself changes length — 46 half-hour columns when an hour disappears, 50 when an hour repeats — because each row is computed from the real instant, not from a fixed offset.
Can I share a board with someone?
Copy the link. It restores the same people, names, working hours, date and anchor for whoever opens it. Nothing is uploaded; the link itself is the document.
My city is not in the list. What now?
Type the IANA zone instead — Europe/Berlin, Asia/Kolkata, America/Sao_Paulo — or a plain offset like UTC+3 or +05:45. Both always work, including for places the city index does not cover.
How many people can I put on one board?
Up to twelve. Past that the bands stop being readable, and in practice a meeting with more than twelve time zones in it needs a recording, not a slot.
Can each person have different working hours?
Yes. Set them on the row, including windows that cross midnight for night shifts. They travel in the link with everything else.
What if there is no hour when everyone is awake?
Overlap says so plainly instead of inventing a green column, then offers the least-bad hour and names who would be asleep for it. The fair rotation view helps you spread that cost across a team over several weeks.
Does it work on a phone?
Yes. The board scrolls inside its own frame, the rows stay readable at small widths, and the light and dark themes follow your system setting.
Is it really free?
Yes — free, no ads, no account, no usage limit. It is a small tool from a small studio, and it costs us almost nothing to run because it does its work in your browser.
Open the board
Add two people and a city you keep getting wrong. It takes about fifteen seconds to see whether a good hour exists.
Part of Autofract. Overlap is one of a handful of small, sharply focused tools we build and give away. See the other tools →