Files
bgclock/public_html
hansdezwartandClaude Opus 5 f68a88f3e8 Centre the reset glyph in its viewBox
The armed ring looked a couple of pixels low. The ring was already exactly
centred on the button — measured 0.00px off — but the glyph wasn't: its arc
is a circle centred at (12,11) in a 24-unit viewBox, so the ring and the
glyph's circle were drawn as two almost-concentric circles about 1.8px
apart, which reads as misalignment much louder than a single shape would.

Shifting the glyph down one unit puts its circle at (12,12), concentric with
the ring to 0.00px. It also fixes the icon sitting high next to its
neighbours — reset was the only one in the bar whose ink was off centre
(dy=-1.32 against 0.00 for the gear and speaker).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-11 11:46:45 +02:00
..
2026-08-11 10:52:35 +02:00
2026-08-11 10:52:35 +02:00
2026-08-11 10:52:35 +02:00
2026-08-11 10:52:35 +02:00

Backgammon Clock

A two-player match clock with simple delay you can actually see. Reserve time plus a fixed number of free seconds each turn that never carry over — the Backgammon Galaxy control. Defaults to 3:00 + 15s.

Plain HTML, CSS and JavaScript. No frameworks, no fonts, no images, no network.

Getting it onto your phone

Chrome will only offer a real install over HTTPS, so the file needs a host. GitHub Pages is free and takes about two minutes:

  1. Create a new public repository, e.g. bgclock.
  2. Upload all six files to the root: index.html, manifest.webmanifest, sw.js, icon-192.png, icon-512.png, icon-maskable-512.png.
  3. Settings → Pages → Source: Deploy from a branch → main / (root) → Save.
  4. Wait a minute, then open https://<you>.github.io/bgclock/ in Chrome on Android.
  5. Chrome menu (⋮) → Add to Home screenInstall.

Open it from the home-screen icon and it runs fullscreen with no browser chrome, offline, with the screen kept awake while a game is on.

If you're using a different path than /bgclock/, edit the "id" field in manifest.webmanifest to match, or just delete that line.

To try it before hosting, open index.html in any browser — everything works except installation and the service worker.

Using it

  • Tap your own half to end your turn and start your opponent's clock. At the start, whoever taps first sets the other player going.
  • The waiting player's taps are ignored, so a stray hand won't stop the clock.
  • The bar under the big time is the delay draining. When it empties you get a soft tick and your reserve starts moving. That's the moment worth hearing.
  • Reset returns to the starting position. It takes two taps: the first arms the button — it lights up and a ring unwinds around it — and a second tap within those two seconds does it. One stray thumb can't wipe a live game.
  • Pause freezes mid-turn and resumes exactly where it stopped, delay included. Opening settings pauses automatically, and leaves it paused so the clock only restarts when both players are ready.

Backgammon clocks pause between games, and after a cocked die the delay is normally restarted — use pause and reset for those.

Settings

At the top of the sheet are two presets — 2m / 12s and 3m / 15s. Tapping one jumps both timers there and lights it up. Change the time or delay by hand and the highlight goes out; land back on a preset's numbers and it comes back on.

Setting Range Default
Time 0:15 99:00 3:00
Delay 0 60 s 15 s
Colour Sage, Brass, Slate, Teal, Plum Sage
Sound on / off on

Brass is the colour in the chess.com app, if you want the exact original look. Changing time or delay resets the clock. Settings are kept in localStorage, so they survive closing the tab, force-quitting the installed app and rebooting the phone — the app also asks for persistent storage so they aren't evicted when the device runs low on space. Only the settings are stored; a game in progress isn't.

Sounds

All three are generated with the Web Audio API, so there are no audio files to download and nothing to attribute.

  • Turn change — a soft rising fifth with an octave partial, marimba-like.
  • Delay expiry — a single quiet 300 Hz tick, deliberately easy to miss unless you're listening for it.
  • Time out — a falling triad, loud and unambiguous.

Licence

Do whatever you like with it.