https://github.com/timoheimonen/clocksimulator
A clean, sustainable, open-source, embeddable, and fullscreen analog clock simulator. No ads, no tracking, just a beautiful clock.
https://github.com/timoheimonen/clocksimulator
cloudflare-pages css html iframe-embeds javascript localstorage minimalist multirow-items no-account no-ads no-tracking screen-wake-lock sustainability themes url-parameters
Last synced: 3 months ago
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A clean, sustainable, open-source, embeddable, and fullscreen analog clock simulator. No ads, no tracking, just a beautiful clock.
- Host: GitHub
- URL: https://github.com/timoheimonen/clocksimulator
- Owner: timoheimonen
- License: mit
- Created: 2026-02-24T19:51:04.000Z (4 months ago)
- Default Branch: main
- Last Pushed: 2026-03-20T20:43:45.000Z (4 months ago)
- Last Synced: 2026-03-21T11:40:38.074Z (3 months ago)
- Topics: cloudflare-pages, css, html, iframe-embeds, javascript, localstorage, minimalist, multirow-items, no-account, no-ads, no-tracking, screen-wake-lock, sustainability, themes, url-parameters
- Language: HTML
- Homepage: https://www.clocksimulator.com
- Size: 913 KB
- Stars: 14
- Watchers: 0
- Forks: 3
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# clocksimulator
[](https://github.com/timoheimonen/clocksimulator/stargazers)
[](https://github.com/timoheimonen/clocksimulator/network/members) [](https://www.websitecarbon.com/website/clocksimulator-com/)
A clean, fullscreen analog clock simulator built with plain HTML, CSS, and JavaScript.
This is a minimalist, old-school web page with no trackers, no cookies, and no extra bloat. Just a pure analog clock, nothing more.
## Goals
- Privacy first
- Keep it light and fast
- No ads or tracking cookies, ever
- No user accounts
- No backend
- No 3rd party libraries, only HTML/JS/CSS that can run even offline
- Free for everyone
- Make it as maintenance free as possible
- Just a clock, nothing more or less
## Timezone support
By default the clock shows your local time. To display a different timezone, add the `tz` query parameter with any valid [IANA timezone identifier](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones):
```
https://clocksimulator.com/?tz=America/New_York
https://clocksimulator.com/?tz=Asia/Tokyo
https://clocksimulator.com/?tz=Europe/Helsinki
https://clocksimulator.com/?tz=UTC
```
If the value is invalid or omitted, the clock falls back to your local timezone.
## Multi-clock dashboard
Show multiple clocks at once by separating timezones with commas:
```
https://clocksimulator.com/?tz=UTC,Europe/Helsinki,America/New_York
https://clocksimulator.com/?tz=UTC,Europe/Helsinki,America/New_York,Asia/Tokyo&rows=2
```
The grid layout is calculated automatically. Use the optional `rows` parameter to control the number of rows.
You can also build it visually: click the **info button** on [clocksimulator.com](https://clocksimulator.com) and select **Build dashboard** to open the dashboard builder with live preview and a copy-ready link.
Feature of easy url with multiple timezones requested by "Hacker News" user "elteto".
## Embed
You can embed the clock on any website using an iframe. Click the **info button** on [clocksimulator.com](https://clocksimulator.com) and select **Embed this clock** to open the generator with a live preview and copy-ready code.
### Quick start
Round (default):
```html
```
Square:
```html
```
Custom border radius:
```html
```
The shape is controlled via the iframe's CSS `border-radius` — use `50%` for round, `0` for square, or any value like `8px`, `16px` for rounded corners.
### Parameters
All parameters are optional and can be combined:
| Parameter | Values | Default | Description |
|------------|--------|---------|-------------|
| `embed` | `true` | — | Activates embed mode (hides UI controls) |
| `tz` | IANA timezone(s), comma-separated | Local time | Timezone(s), e.g. `Europe/Helsinki` or `UTC,Europe/Helsinki,America/New_York` |
| `rows` | Number | Auto | Number of grid rows for multi-clock dashboard |
| `theme` | `dark`, `light`, `transparent` | OS preference (light fallback) | Color theme |
| `seconds` | `tick`, `smooth`, `hide` | `tick` | Second hand mode |
| `border` | `show`, `hide` | `show` | Clock border visibility |
| `daynight` | `show`, `hide` | `hide` | Sun/moon indicator for day/night |
| `numbers` | `show`, `hide` | `show` | Clock numbers visibility |
| `shadows` | `true`, `false` | `true` | Hand and center dot shadows |
| `burnin` | `true`, `false` | `true` | Screen burn-in protection (pixel shift) |
### Examples
```
https://clocksimulator.com/?embed=true&tz=Asia/Tokyo&theme=light
https://clocksimulator.com/?embed=true&seconds=smooth&border=hide
https://clocksimulator.com/?embed=true&tz=America/New_York&theme=dark&seconds=hide
```
## Accessibility
When the operating system's **prefers-reduced-motion** setting is active, the second hand and clock hand shadows are automatically disabled to reduce on-screen animation.
## Chrome extension
Chrome extension is also available at [Google Chrome web store](https://chromewebstore.google.com/detail/clocksimulatorcom/ljbpiigocbebamekohcpemgepjickldb).
Extension replaces new tab page with analog clock.
[GitHub repo](https://github.com/timoheimonen/chrome-extension-clocksimulator) also available.
Extension follows main clocksimulator.com version, but not always updated 1:1 and might vary in features.
## Privacy & Terms of service
- [`clocksimulator.com/privacy.html`](https://clocksimulator.com/privacy.html)
- [`clocksimulator.com/TOS.html`](https://clocksimulator.com/TOS.html)
## License
MIT. See `LICENSE`.
## Author
Timo Heimonen