A clean browser-only accuracy panel for your device clock. TimeWithSeconds keeps the display fresh and automatically resyncs after sleep, tab changes, and mobile backgrounding.
This static version reads your device time directly. No server is needed, and the clock refresh loop restarts automatically if the browser pauses it.
No server time check in this static build. A future optional Cloudflare Worker can compare your device clock with network time using only a few pings on demand.
A clock page can be left open for hours. This build automatically restarts the update loop when the tab wakes, the device returns from sleep, or the browser throttles animation frames.
This page checks your browser display refresh and device-clock behavior. TimeWithSeconds updates from your device clock and automatically resyncs the display when the tab becomes active again.
For official atomic accuracy, your operating system must be synchronized with network time. A browser-only static page cannot independently prove atomic-clock accuracy without an optional network reference.
時計精度チェック. 秒付きの正確な現地時刻を、見やすいライブ時計で確認できます。全画面、時計同期、協定世界時（UTC）、24時間表示、世界時計、オフラインアプリモードに対応しています。
時計精度チェック. 秒付きの正確な現地時刻を、見やすいライブ時計で確認できます。全画面、時計同期、協定世界時（UTC）、24時間表示、世界時計、オフラインアプリモードに対応しています。
