Time-Deck: Free Full-Screen Clock, Countdown Timer, Stopwatch & World Clock

Time-Deck shows full-screen clocks, countdowns, stopwatches, world clocks and stage timers on any screen: a laptop, TV, projector or OBS stream. You set it up from a dashboard. It runs entirely in your browser with no server, no account and no tracking, and it works offline as an installable PWA.

▶ Open Time-Deck

Contents

• Features
• Screenshots
• Use cases
• Display & styles
• Keyboard shortcuts
• Sharing, second screen & OBS overlay
• Privacy
• How time is kept
• Development
• Deployment
• Contributing
• Credits

Features

Group	Mode	What it does
Clocks	Clock	Digital or analog, seconds and date, any city, optional UTC / ISO week / Unix time
	World clocks	Up to 12 cities in an auto grid, offset vs local time, tomorrow/yesterday, day/night tint, sunrise & sunset
	World map	Live day/night terminator, subsolar point and city pins (computed offline)
	Meeting planner	24h strips per city with working hours, overlap highlight, click-to-select + copy, time converter
Timers	Countdown	Duration with quick chips, progress ring, amber/red thresholds, overtime count-up
	Event countdown	Days/hours/minutes to a date in any time zone, then "time since"
	Stopwatch	Centiseconds, laps with lap/split, best/worst highlight, CSV export
	Presenter	Agenda segments, colour thresholds, overtime flash, live messages to the speaker
	Pomodoro / intervals	Pomodoro sets or custom HIIT-style intervals with repeat
	Multi-timer	Up to 12 independent countdowns/stopwatches, tap a tile to start/pause
	Exam / classroom	Manual or fixed start/end, reading time, spoken milestones, notice board
Fun	Word clock · Binary clock · Progress (day/week/month/year) · Moon phase

Alarms and "remind me in X" reminders work on top of any mode. They ring only while a Time-Deck tab is open.

The interface is available in English, Spanish, French and German, and supports 12-hour (AM/PM) and 24-hour time.

Screenshots

Clock	Clock, Flip style
Countdown, Neon style	Event countdown, Aurora style
World clocks	World map
Meeting planner	Stopwatch with laps
Presenter / stage timer	Exam / classroom
Multi-timer	Word clock
Moon phase

Use cases

• Classrooms and exams: a big "time left" display with reading time, spoken milestones and a notice board.
• Conferences and events: a presenter or stage timer on a confidence monitor, with agenda segments and live messages to the speaker.
• Streaming: a transparent OBS browser-source overlay for countdowns and clocks.
• Remote teams: world clocks, a day/night map and a meeting planner that finds overlapping working hours.
• Focus and workouts: Pomodoro cycles and custom interval (HIIT) timers.
• Offices and lobbies: a full-screen wall clock on a spare TV, with burn-in protection.

Display & styles

• Present switches the current tab to full screen. Open display window opens a second window (TV or projector) that stays in sync through BroadcastChannel, with a localStorage fallback.
• 7 display styles: Minimal, Glass, Neon, Flip, LED, Aurora and High contrast. Each works in light and dark, with an accent colour, 4 bundled fonts, a size slider, and a solid, gradient or image background.
• Screen Wake Lock, cursor and controls auto-hide, burn-in pixel shift, large-touch mode with swipe between modes.

Keyboard shortcuts

Key	Action
Space	Start / pause
R	Reset
L	Lap
↑ / ↓	±1 minute
N / P	Next / previous segment
PgDn / PgUp	Presentation clicker
F	Full screen
T	Toggle theme
H	12h / 24h
?	Help

Sharing, second screen & OBS overlay

• Share link: the whole setup is compressed into #/display?s=…. The link opens isolated from local settings, and a QR code is shown for phones.
• OBS overlay: add &embed=1&bg=transparent, plus optional &scale=, &align= and &color=.
• Presets: saved in localStorage, with JSON export and import.

Privacy

Everything runs locally in your browser. There is no backend, no sign-up, no analytics and no cookies. Settings and presets stay in your browser's localStorage, and a share link only contains the setup you chose to share.

How time is kept

Timers never accumulate setInterval ticks. A running timer stores { anchor, acc }, and elapsed time is acc + (now - anchor). That keeps it accurate in throttled background tabs, after a reload, and across synced windows. Timer events (end, warnings, phase changes, exam milestones) are derived from this state in src/lib/signals.ts and fire once per window. Only the display window, or the dashboard when no display is open, plays sound.

Development

Requires Node.js 20.19+ (CI uses Node 24).

npm install
npm run dev        # http://localhost:5173
npm test           # vitest: time math, DST, meeting overlap, alarms, solar/moon, signals
npm run lint
npm run build      # → dist/ (static, base './')

Structure

src/
  lib/        pure logic: time, tz, solar, alarms, sequence, signals, share, sync, audio
  store/      zustand store (persist + cross-window sync), actions, defaults
  modes/      one file per mode: Display + Settings (lazy-loaded)
  components/ DeckView (display shell), ControlBar, Engine (events/alarms), UI primitives
  dashboard/  dashboard page + panels      display/  full-screen page
  i18n/       t('key', 'English') with es / fr / de dictionaries
  styles/     tokens, dashboard, deck styles, per-mode layouts

Built with React 19, TypeScript, Vite, Zustand, SCSS and vite-plugin-pwa.

Deployment

Every push to main runs .github/workflows/deploy.yml, which installs dependencies, runs the tests, builds dist/ and publishes it to GitHub Pages at https://chrisjdj.github.io/Time-Deck/.

One-time setup: Settings → Pages → Build and deployment → Source: GitHub Actions.

The build uses relative paths (base: './'), so dist/ can also be hosted from any static server or sub-folder.

Contributing

Issues and pull requests are welcome. See CONTRIBUTING.md for setup, checks, and how to add a language or a mode.

Credits

• Land outlines: Natural Earth via world-atlas (public domain)
• Sun/moon times: SunCalc (BSD-2)
• Flag glyphs on Windows: Twemoji Country Flags (CC-BY 4.0, Twitter/Twemoji)
• Icons: Lucide (ISC)

License

MIT