Open World Clock
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A World Time Buddy alternative for Windows

Compare times in your browser, or keep them above your work in the free Windows app. Here’s how Open World Clock and World Time Buddy compare.

Get it from Microsoft Store See all features
  • Free
  • Native Windows app
  • Works offline
  • No account
Open World Clock with six city cards: Lisbon (Home) and London at 14:20 in the afternoon, New York at 09:20 in the morning, San Francisco at dawn, Tokyo and Sydney at night.

Side by side

Swipe to see the other columns

FeatureOpen World ClockWorld Time Buddy
PriceFree, MIT open source, no adsFree website, with ads
Where it livesWindows desktop or browserA browser tab
Windows appYes, for Windows 10 and 11No, you use the website
Hour grid with every cityYes, the meeting plannerYes, its signature hour tiles
Working hours and days per cityYes, night shifts included, with the overlap outlinedNot in the same way
Convert a timeType 3pm in any city, or scroll the mouse wheelPick an hour on the grid
Stays above other windowsYes, if you pin itNo, it’s a tab
Works offlineWindows app: yes. Browser: connection needed to load.No, the website needs a connection
AccountNone, everOptional sign-in to keep your settings
Share the resultCopy times, export a calendar event, or share a browser linkA link to your current view
Runs onWindows 10 and 11; any modern browserAny browser, phones included (its iPhone and Android apps haven’t been updated since 2020)

Based on worldtimebuddy.com in September 2026. World Time Buddy may have changed since; tell me if something here is out of date.

What World Time Buddy does well

The hour grid is a great idea, and World Time Buddy does it well: a row of hours for each city, lined up, so the hour that suits everyone jumps out. It works in any browser, phones included, and you can send a colleague a link to exactly what you see.

If you plan meetings from your phone, or on a computer where you can’t install anything, it’s a good choice. On a PC you can’t install software on, you can also try Open World Clock live in the browser.

Why a Windows app for the same job

If you work with people in other time zones every day, a browser tab is one more thing to find, reload and sign in to. Open World Clock keeps your cities on the desktop, above every window if you pin it, and it answers “what time is it there?” without opening anything.

It runs on your PC, so it works offline, loads nothing from the internet and has no ads, no account and no telemetry. The code is open, MIT licensed, on GitHub.

The hour grid, with working hours

The meeting planner lines up a 24-hour row for each of your cities and outlines the hours when everyone is at work.

The meeting planner for Lisbon, London, New York and San Francisco on Wednesday 23 September: a 24-hour row per city, with the two shared working hours, 16:00 to 18:00 in Lisbon, outlined.
Swipe sideways to see the whole day.
“2 h overlap · 16:00 to 18:00 (Lisbon)”, in the Windows app.

  • Working hours per city

    Each city keeps its own start, end and working days, so an office that works Sunday to Thursday or a night shift fits in.

  • The overlap, summed up

    Shared working hours are outlined, with a line like “2 h overlap · 16:00 to 18:00 (Lisbon)”.

  • When nothing fits

    It outlines the hours when the most cities are at work, for example “Best: 12:00 to 13:00 (New York), 4 of 5 working”.

  • Daylight saving, per day

    Each day uses its own rules, so the weeks when Europe and the US change clocks on different dates come out right.

How the meeting planner works

Converting a time

Type a time such as 3pm, 9:30 or 15h30, pick the city it belongs to, and every clock shows the matching time, with +1 day where the date changes. Or turn the mouse wheel over any card to move every city in 15-minute steps. Copy times puts the whole list on the clipboard, ready to paste into an invite. More about the time zone converter.

Which one should you use?

  • On your phone, or on a computer you can’t install anything on: Both work in the browser. Open World Clock also offers a free, offline Windows app.
  • A link to send someone: Both can share a link. Open World Clock can also copy times and export a calendar event.
  • Your cities in view all day on a Windows PC, and meetings across them, offline and without ads: Open World Clock.

World Time Buddy is a trademark of its owner. Open World Clock isn’t affiliated with World Time Buddy or with Microsoft.

More about Open World Clock

Put the world on your desktop

Completely free for Windows 10 and 11. Open source, no account, no ads, no telemetry.

Get it from Microsoft Store Other downloads

Support the creator on Ko-fi

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