Meridian

A world clock that puts two destinations side by side — each with its own flag waving behind the time, the current UTC offset, and how far apart the two are.

Open in your browser · Download for desktop · How it works

Nothing to install to try it. Your browser can also keep it as a real app — see Install from the browser.

Meridian is source-available: free to run and modify for your own and your company's internal use, and the code is here to read. It is not open source — see Licence.

What it does

• Live local time for two destinations, to the second, from one shared instant
• 200 countries and territories, 245 cities — every country spanning several time zones lets you pick the city (Brazil has 8, the US 7, Russia 7)
• Handles daylight saving automatically, and offsets that aren't whole hours (Nepal is UTC+5:45, India UTC+5:30)
• Says the difference in plain words: "Israel is 6h ahead of Brazil", and flags when the two are on different calendar days
• Search by country or city, accent-insensitive — typing sao finds São Paulo
• Flags wave like cloth; the motion can be paused, and it respects your system's reduced-motion setting
• Follows your light/dark theme
• Remembers your destinations, the wind setting and the pin between sessions

Install from the browser

On the live page:

Chrome / Edge (Windows, Linux, macOS)	Click the install icon in the address bar, or menu → Cast, save and share → Install page as app
Android	Menu → Add to Home screen
iPhone / iPad	Share → Add to Home Screen

It opens in its own window, with no address bar, and works offline after the first visit. No download, no security warnings.

Desktop apps

Native windows with no browser chrome — and a pin button that keeps the clock above other windows, which the browser version cannot do.

Grab one from the latest release:

System	File	First launch
macOS 11+	Meridian-macOS.zip	Right-click the app → Open (once)
Windows 10/11	Meridian-Windows.zip	More info → Run anyway (once)
Linux (GTK)	Meridian-Linux.tar.gz	./install.sh

That extra click on the first launch is the unsigned-app warning. Code signing certificates cost money every year and this project has none — the warning is about a missing certificate, not about the app.

Window controls: 📌 keep on top · − minimize · × close (⌘W / Ctrl+W also work). Drag the window by its header or footer.

Building it yourself

The app itself is one file, index.html, and needs no build step at all — open it and it runs. Each desktop wrapper is a thin native shell around it:

# macOS — needs Xcode command line tools
./desktop/macos/build.sh

# Windows — needs the .NET 8 SDK (winget install Microsoft.DotNet.SDK.8)
.\desktop\windows\build.ps1

# Linux — no build, just system packages
sudo apt install python3-gi gir1.2-webkit2-4.1   # Debian/Ubuntu
./desktop/linux/install.sh

Or let GitHub build all three: push a tag and the release workflow compiles on macOS, Windows and Linux runners and publishes the files.

git tag v1.0.0 && git push origin v1.0.0

How it's put together

index.html              the whole app — layout, clocks, catalog, flag animation
manifest.webmanifest    lets browsers install it as an app
sw.js                   offline cache
icons/                  app icons
desktop/macos/          Swift + WebKit wrapper
desktop/windows/        C# + WebView2 wrapper
desktop/linux/          Python + GTK/WebKitGTK wrapper

All three wrappers answer the same four messages from the page — close, minimize, drag, pin — plus fit on Windows, which sizes the window to the card because its frame cannot be transparent.

Time is computed with Intl.DateTimeFormat over IANA time zone identifiers, so daylight saving and odd offsets come from the system's own tz database rather than from hardcoded rules.

Contributing

Bug reports, fixes and ideas are welcome. Start at CONTRIBUTING.md — it covers how to report a problem, the code conventions, what to test, and how review works.

Security problems go through SECURITY.md instead of public issues.

Credits

• Flags — flag-icons by Panayiotis Lipiridis (MIT)
• Type — Manrope by Mikhail Sharanda and DM Sans by Colophon Foundry (both SIL OFL 1.1)
• Time zones — the IANA time zone database, via the browser's Intl API
• Country codes — ISO 3166-1 alpha-2

Licence

Meridian is source-available software, not open source. The code is public to read, study, run and modify — but it is not published under an OSI-approved open source licence, and it does not turn into one later. Calling it open source would be inaccurate, so this project does not.

It is licensed under the PolyForm Internal Use License 1.0.0, a standard licence written by lawyers. The full text is in LICENSE.

Free, no licence to request:

• running Meridian yourself, on any device
• your team or your entire company running it internally
• reading the code and learning from it
• modifying it for your own internal use
• forking it to send a pull request — granted explicitly in LICENSE

Needs a commercial licence:

• selling it, or charging for access to it
• shipping it inside a product or service you offer to customers
• hosting it as a service reachable from outside your organization
• redistributing it through a store, registry or installer

The boundary between the two, with each term defined, is in COMMERCIAL.md — including how to ask. Asking is free, and the answer is often "what you are doing is already covered".

Third-party material and its licences are listed in NOTICE.

Maintainer

Meridian is created and maintained by Wallace Ferreira de Abreu (@wallasace), who holds the copyright.

Copyright © 2026 Wallace Ferreira de Abreu

Contributors keep the copyright in their own contributions — see CLA.md. Forks are welcome under the terms above, and a fork does not imply endorsement by this project.