Neiki's Time

Ultra-Precise Time Display
NTP-synced, drift-free, framework-free — just one script tag.

⭐ Enjoying Neiki's Time? Give it a Star and Fork the repository! ❤️
Your support helps me see that the project is useful to developers
and motivates me to keep improving it with more frequent updates.

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Live demo: https://neikiri.dev/time

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⚡ Quick Start (CDN)

Add two lines to any HTML page — no build tools, no frameworks, no dependencies:

<div data-neiki-time></div>
<script src="https://cdn.neikiri.dev/neiki-time/neiki-time.min.js"></script>

That's it. The clock syncs automatically and starts ticking.

Unminified version also available at https://cdn.neikiri.dev/neiki-time/neiki-time.js

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🔧 Configuration

NeikiTime.init({
  selector: '[data-neiki-time]',  // CSS selector for clock elements
  timezone: 'Europe/Prague',       // IANA timezone (undefined = local)
  locale: 'cs-CZ',                // Intl locale
  showDate: true,                  // show date part
  showMs: true,                    // show milliseconds
  showOffset: false,               // show sync debug info
  syncInterval: 60000,             // re-sync interval in ms
  syncSamples: 3,                  // samples per API per sync round
  theme: 'auto',                   // 'light' | 'dark' | 'auto' | 'none'
  onSync: function(info) {},       // callback after successful sync
  onTick: function(date) {}        // callback every animation frame
});

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📌 Data Attributes

Per-element overrides via HTML attributes:

Attribute	Description
data-neiki-time	Marks element as a clock (required)
data-neiki-tz="Asia/Tokyo"	Override timezone for this element
data-neiki-nodate	Hide the date part
data-neiki-noms	Hide milliseconds
data-neiki-offset	Show sync offset & RTT debug info

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📡 JavaScript API

Method	Returns	Description
NeikiTime.init(options?)	—	Initialize and start rendering
NeikiTime.destroy()	—	Stop everything, release resources
NeikiTime.sync()	Promise	Trigger manual re-sync
NeikiTime.now()	number	Precise UTC timestamp in ms
NeikiTime.date()	Date	Precise Date object
NeikiTime.isSynced()	boolean	Whether time has been synced
NeikiTime.getSyncInfo()	object|null	Last sync info (offset, rtt, api)

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🧠 How It Works

1. Parallel queries to multiple public time APIs (WorldTimeAPI, TimeAPI.io)
2. Multiple samples per API — selects the one with the lowest round-trip time
3. NTP-style offset: offset = serverTime − (t0 + rtt/2)
4. Anchors to performance.now() for monotonic, drift-free ticking
5. requestAnimationFrame() for smooth ~60 fps rendering
6. Periodic re-sync (default every 60 s) to correct any residual drift

Typical accuracy: ±15–80 ms depending on network latency. Between syncs, performance.now() guarantees zero drift.

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📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

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👨‍💻 Author

neikiri GitHub: https://github.com/neikiri

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📬 Contact

📧 Email: neikiri@neikiri.dev