World Clock & Time Zone Converter
A world clock and time zone converter with a meeting planner that finds the hour everyone is at work, then copies the slot in each city's own local time.
There is no slot to propose yet — drag the planner or type a time.
No hour works for everyone today
Both halves
Your clocks
Meeting planner
What a touch drag does
Drag across the hours, tap one, or type From and To — a slot snaps to the quarter hour.
How to use
- Add the places you care about from the box marked Add a city or time zone. It holds hundreds of entries, so a search field opens with it and typing a few letters of the city is faster than scrolling.
- Leave Date empty while you just want live clocks. They turn over every minute.
- To convert instead, choose a zone under Convert from, pick a Date, and enter a time in From. Everything on the page moves to that instant.
- Set Working hours from and to for the people you're scheduling with. The green on the grid follows those two selects, and they may run past midnight.
- Read the line under the big clock for the hour that works for everyone, then drag across that column, or tap it on a phone. The band snaps to 15 minutes and every row in the list shows what the slot is locally.
- Press Copy meeting proposal for the text version, or Copy share link for a link that reopens this exact grid.
About this tool
Five clocks are already on the page the first time you open it: your own zone, UTC, New York, London and Tokyo. The Add a city or time zone box above the list takes any of the others your browser knows about, which is the full IANA set, and the ✕ on a row drops one you don't want. Each row carries the city, its UTC offset, how far ahead or behind your source zone it sits, and the local date with a Today, Tomorrow or Yesterday marker. The big clock at the top is the zone you convert from, and every clock turns over on the minute without a reload.
Filling in a Date turns the live clocks into a conversion. Say 9:00 on a Tuesday in New York. Every row rewrites itself to what that same instant reads locally, offsets included, so a January date gets January's offsets even in July. Picking a source zone that isn't already on the page slots it in at the top of the list for you. Clear empties the date and the meeting and puts the clocks back on live.
Below the list sits the meeting planner, which is the part I actually built this for. It lays each zone out as a row across 24 hours of the source day. Working hours are green and default to 9 to 5, the hours from 10pm to 7am are shaded as night, and the planner works out the hour where every row is green, marks it in the heading and says so under the big clock. When no such hour exists it tells you which two cities never meet. Working hours that run overnight, a 10pm to 6am shift say, shade across midnight, and a day where the clocks jump forward draws the missing hour as missing. Drag across the hours and the band snaps to quarter hours, a plain click books an hour from where you clicked, and the arrow keys walk the grid with Enter to book. On a phone the grid turns, hours running down and cities across, so a tap on an hour books it.
Once the band is where you want it, Copy meeting proposal puts a plain-text block on the clipboard: the length of the meeting, then a line per city with its local date and start and end times. Copy share link beside it copies a link instead, and that link carries the zones, the working hours, the day and the slot, so whoever opens it sees the same grid. A meeting may run past midnight, and the line under the clock then names both days. Offsets come from the browser's own time zone database, so a January conversion and a July one get different answers for the same city when that city observes daylight saving.
A worked slot
New York and Kolkata, Thursday 15 January 2026. Set Convert from to New York, put 2026-01-15 in Date, then type 09:30 into From and 10:00 into To. The line under the big clock reads 9:30a – 10:00a · 30m in New York.
New York is on UTC-5 that week and Kolkata is on UTC+5:30 all year, so the Kolkata row shows +10h 30m and 8:00 PM. Copy meeting proposal gives you: Proposed meeting time (30m), then New York: Thu Jan 15, 9:30 AM – 10:00 AM, then Kolkata: Thu Jan 15, 8:00 PM – 8:30 PM.
Good to know
- A shared link is a snapshot. If the other person moves the meeting in their copy, nothing comes back to yours.
- Your home clock is only as right as your operating system's clock and zone setting. Every difference on the page is measured against it.
- Daylight saving rules come from whatever version of the time zone database your browser shipped with. Governments sometimes change the rules with a few weeks' notice, and browsers can be an update behind.
- Public holidays are not marked. An hour where everyone is inside working hours can still be a national holiday in one of the cities, so check the calendar before you send the invite.
Frequently asked questions
What time is 9am EST in IST?
Set Convert from to New York, pick your date, type 09:00, and read the Kolkata card. In winter that's 7:30 PM the same day; in July, when New York is on EDT, the same 9am reads 6:30 PM. The difference label on the card spells it out as +10h 30m or +9h 30m.
How do I find a time that works for a team split across three continents?
Add every zone involved and set the working hours you want to respect. The planner works out the hours where every city is inside them, marks them in the grid's heading and names them under the big clock. If there isn't one it says so and names two cities that never meet; widen the working hours by an hour at each end and it checks again, because somebody is going to have to take it early or late.
Can I book 45 minutes, or does it only do whole hours?
Quarter hours are the unit everywhere. A drag snaps to 15-minute boundaries, the From and To inputs step in 15 minutes, and the line under the big clock updates as you go, so 45 minutes starting at half past is a normal thing to pick. A single click without dragging is the one shortcut that assumes an hour.
Does it get daylight saving right on its own?
Yes, and it does it per date and per hour rather than per city. The offset is looked up for the exact day and hour you're converting, which is why a fixed offset chart quietly goes wrong for a fortnight each spring and autumn when countries change over on different weekends. On the day the clocks go forward, the hour that never happens is drawn as missing and the planner calls it a 23-hour day.
How do I send the agreed time to everyone without them doing the maths again?
Copy meeting proposal writes out the block you selected, one bullet per city, each with its own weekday, date and start-to-end times. Paste that into the thread and nobody has to convert anything. The separate share button copies the URL instead, which carries your zone list and the selected range, so a colleague opens the same grid you are looking at.
Are the cities I add still there next time?
Your zone list, the 12-hour toggle and the working hours are saved locally, so the page reopens the way you left it. They stay on the one browser though. Moving your setup to a phone means copying the share link across, since the link carries the same zones.
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