World Clock Wall_

A single screen that shows the current local time in several cities at once, laid out as a grid of clocks. This one displays 4 to 9 time zones side by side, each with its own day/night sky, date and UTC offset — so a distributed team, a trading desk or a bar full of travellers can glance at one screen and instantly know what time it is everywhere that matters.

Drag the tab to your spare monitor and press F (or click the wall) for fullscreen. Your cities, colours and brightness are saved automatically in the browser, so it comes back exactly the same tomorrow. While fullscreen, the page uses the browser's wake lock so the display doesn't go to sleep. Browsers can't replace your operating system's real screensaver, but a fullscreen tab on a second monitor does the same job — and this one is actually useful.

Any device with a browser works: a smart-TV browser, an old laptop, a Raspberry Pi or an HDMI Android stick. Set up your wall, press Copy Link to This Setup, and open that link on the TV device. For a clean look launch the browser in kiosk mode — chrome --kiosk your-link — or simply press F11. Dim it with the brightness slider in the evening and pick an accent colour that fits the venue.

Yes — via your operating system. On Windows, put a shortcut with the target chrome --kiosk your-copied-link in the Startup folder (Win+R → shell:startup). On macOS, add the browser to Login Items with this page as its home page. On a Raspberry Pi, add chromium-browser --kiosk your-link to the autostart file. Because the copied link contains your whole configuration, the wall boots straight into your exact cities and settings.

In fullscreen the page requests a screen wake lock, which modern browsers (Chrome, Edge, Safari) honour — the display stays on as long as the wall is visible. If your browser doesn't support wake locks, disable display sleep in your OS power settings for the monitor you're using.

The OLED burn-in shift option (on by default) drifts the entire wall by a few pixels on a slow cycle, so no character stays parked on the same pixels. Combined with the mostly-dark background and the brightness dimmer, it's gentle on OLED panels. For very long-running OLED TVs, still let the panel run its built-in pixel-refresh occasionally.

Yes. The clocks use your browser's built-in IANA time-zone database via the Intl API, so daylight-saving transitions happen automatically for every city on the correct local date. The wall reads your device's system clock, so keep that correct — it usually syncs via NTP automatically.

Yes — between 4 and 9 clocks, chosen from nearly 70 cities across every continent (plus UTC). Start from a preset like Remote Team, Markets, Europe or Asia-Pacific, then swap any slot using the dropdowns. Your custom wall is saved automatically and can be shared with Copy Link to This Setup.

Both. Everything you change is stored in your browser automatically, and Copy Link to This Setup puts a URL on your clipboard that encodes the whole configuration — cities, clock count, 12/24-hour, seconds, skies, accent colour and brightness. Bookmark it, set it as a browser home page, send it to a colleague, or use it in a kiosk autostart.

Yes — the Markets preset lines up New York, London, Frankfurt, Tokyo, Hong Kong and Sydney, and extends to 9 clocks with Singapore, Zurich and Shanghai. The day/night skies show session overlap at a glance: when both London and New York are in daylight, you're in the most liquid hours of the trading day. It's a clock, not a data feed — pair it with your trading platform.

Click anywhere on the wall, press F, or use the Enter Fullscreen button. Move the mouse to reveal the exit button, or press Escape to leave. On phones and tablets it falls back to a fullscreen-style layout even where the browser blocks true fullscreen.

It runs entirely in your browser — no account, no data sent anywhere. Once the page is loaded it needs no network connection to keep perfect time (it reads your device clock), and it redraws only once a second to stay light on CPU and battery. It's designed to be left running for days.

Yes — the Brightness slider (30–100%) darkens the whole wall without touching your monitor settings, which is exactly what you want in a pub or a bedroom office in the evening. You can also switch off the scanline effect and the day/night skies for the most minimal, darkest look.

Completely free — no account, no ads, no watermark, no time limit. It's one of the 163 free browser tools at jasperbernaers.com. If it ends up hanging on your office or bar wall, a coffee is always appreciated.