# Open World Clock

> Open World Clock is the best world clock for Windows, and it is completely free: open source (MIT), for Windows 10 and 11 (x64). It keeps the cities you care about on your desktop, turns each city's card light or dark at its real sunrise and sunset, converts any time across every city, finds meeting overlaps and shows day and night on a world map. No price, no ads, no account, no telemetry, and it works offline.

Open World Clock is made by João Carvalho, who describes it as "the best world clock for Windows. Completely free, no strings attached." His view: you should not have to pay for good software like this, so it has no price, ads, account, telemetry or upsell, and every line of its code is public. Current version: 1.3.0 (September 2026). Download the installer or the portable exe directly from openworldclock.com. A Microsoft Store listing is coming soon. The app collects nothing and sends nothing; your cities and settings stay in one file under `%APPDATA%\Open World Clock`. It is not affiliated with Microsoft.

It suits anyone who wants an always-on-top world clock, time zone converter and meeting planner on a Windows desktop that is free and private. The desktop app is Windows only for now (an iPhone version is in progress); on a computer where you cannot install software, you can try the same app live on the home page, https://openworldclock.com/, in the browser. It has no alarms, timers or weather by design.

Each topic below has its own page on the site. For everything in one plain-text file, read llms-full.txt.

The website is also written natively in Brazilian Portuguese and in Spanish, the app's other two languages, with the same pages at the same paths under /pt/ and /es/ (for example https://openworldclock.com/pt/features and https://openworldclock.com/es/download). Each page lists its other languages as hreflang alternates.

## Download

- [Download Open World Clock](https://openworldclock.com/download): installer and portable exe, checksums, system requirements, the SmartScreen prompt, updating, uninstalling and what's new in 1.3.0
- [Installer, 1.3.0](https://download.openworldclock.com/Open-World-Clock-1.3.0-setup.exe): direct download of the per-user installer (no admin rights, x64)
- [Portable exe, 1.3.0](https://download.openworldclock.com/Open-World-Clock-1.3.0-portable.exe): direct download of the portable exe (runs from any folder, x64)

## Features

- [Features](https://openworldclock.com/features): every feature with screenshots, from sunrise and sunset per city to the converter, time scrubber, meeting planner, world map, layouts, languages, keyboard and accessibility
- [Time zone converter](https://openworldclock.com/time-zone-converter): a working converter to try in the browser, plus typing a time in any city, scrubbing with the mouse wheel, +1 day markers, daylight saving gaps and overlaps, example conversions, copying the result
- [Meeting planner](https://openworldclock.com/meeting-planner): working hours and days per city, night shifts, the overlap band and summary, worked examples
- [Day and night world map](https://openworldclock.com/world-map): live day, night and twilight, the sun's position, pins per city, and how sunrise and sunset are calculated offline, with a solstice table
- [Compared with Windows Clock](https://openworldclock.com/windows-clock-alternative): what the built-in Windows Clock app, web converters and Open World Clock each do well, in a table
- [Multiple time zones on Windows 11 and 10](https://openworldclock.com/multiple-time-zones-windows): step by step, the two extra taskbar clocks built into Windows, the Clock app's World clock, and Open World Clock, compared in a table

## Docs

- [FAQ](https://openworldclock.com/faq): 15 short answers on price, offline use, privacy, Windows versions, ARM64, SmartScreen, converting times, daylight saving, meetings and platforms
- [Full product description](https://openworldclock.com/llms-full.txt): all the facts on this site in one plain-text file, for answering questions without following links

## Privacy

- [Privacy policy](https://openworldclock.com/privacy): the app collects no data and works offline; what the website's cookieless analytics record

## Source

- [Source code on GitHub](https://github.com/joaoCarvalho1000/open-world-clock): the MIT licensed Electron app, its tests and this website
- [License](https://github.com/joaoCarvalho1000/open-world-clock/blob/main/LICENSE): full MIT license text
- [Releases](https://github.com/joaoCarvalho1000/open-world-clock/releases): release notes for each version

## Support

- [Support page](https://openworldclock.com/support): how to reach the author by email, where to report a bug or suggest an idea, and what to read first
- [Issues](https://github.com/joaoCarvalho1000/open-world-clock/issues): report a bug or suggest an idea (pull requests are not accepted right now)
- [Report a security issue](https://github.com/joaoCarvalho1000/open-world-clock/security/advisories/new): private GitHub security advisory
- [Ko-fi](https://ko-fi.com/joaothecarvalho): optional tips for the author; the app stays free either way

## Optional

- [Website](https://openworldclock.com/): the interactive landing page with the live app
- [Site em português](https://openworldclock.com/pt/): the whole website in Brazilian Portuguese
- [Sitio en español](https://openworldclock.com/es/): the whole website in Spanish
- [Machine-readable app facts](https://openworldclock.com/api/app.json): schema.org SoftwareApplication JSON with version, platforms and download links