Precision Atomic Time – NTP Synced, Private, and Always Accurate
AtomicClock delivers true atomic precision time to your iPhone or iPad by querying public Network Time Protocol (NTP) servers — the same infrastructure used by banks, airlines, and scientific institutions worldwide. The app displays the current atomic time with millisecond accuracy, supports multiple timezones, and offers a precision stopwatch, countdown timers, and customizable alarms — all without collecting any personal data.
Open AtomicClock and it immediately queries public NTP servers to compute the precise offset between your device clock and atomic time. Sync typically completes in under a second.
The main display shows the current atomic time, your local timezone, and the sync quality indicator. Tap any timezone in your list to see the atomic time there.
Switch to the Stopwatch tab to measure intervals with atomic accuracy, or set a countdown timer and alarm. All tools are referenced to the synchronized atomic time.
AtomicClock contacts public NTP servers only to retrieve the current time — no personal data is included in these requests. All user settings and preferences are stored locally on the device. The app contains no analytics SDKs, no advertising networks, and requires no account or login.
AtomicClock is a utility app focused on time accuracy and privacy. It connects to the internet solely for NTP time synchronization using standard UDP port 123 — the same protocol iOS itself uses. There is no user-generated content, no external social features, and no in-app purchases. The app is fully functional without an active network connection, displaying local device time when offline.
If you encounter any issues or have feature requests, please reach out. We value every suggestion and respond promptly to keep AtomicClock accurate and reliable.