Prime Time NTPv1.2

What changed

• PerformanceImplemented full four-timestamp NTP exchange to improve timing accuracy
• PerformanceExcluded name resolution and connection setup from network delay calculations
• PerformanceAdded a clock filter that selects the best of the last eight exchanges
• New featureAdded visual marking for the best server source with accuracy estimates
• PerformanceAdded Wi-Fi and cellular detection with optional radio warm-up
• PerformanceAdded support for honoring Kiss-o'-Death server replies
• New featureAdded Display Legend and Network & Accuracy help screens
• LocalizationAdded Japanese language support
• UXUpdated server list saving to retain entries beyond the free limit
• MonetizationFixed a bug where Pro features appeared unavailable during launch entitlement checks

Original release notes

Version 1.2 is an accuracy release.

• Full four-timestamp NTP exchange. The time a server spends preparing its reply is now read from the packet and removed from the measured delay. Previously it was charged to the network, which pushed the displayed clock forward by half of it on every sync.
• Name resolution and connection setup are no longer counted as network delay, removing a large error from the first measurement after launch.
• Clock filter. Each server keeps its last eight exchanges, and the app relies on the one with the lowest synchronization distance rather than simply the newest.
• Best source marking. A green double ring marks the server with the lowest estimated error. The device offset below the clock is measured from that server and shown with its ± accuracy.
• Wi-Fi and cellular detection, with an optional warm-up on cellular so a radio waking from idle is not measured cold. No fabricated latency correction is applied.
• Kiss-o'-Death replies are honoured: a server reporting that it is being polled too often drops to the slowest interval for the rest of the session.
• Two new help screens — Display Legend, and Network & Accuracy.
• Japanese interface when the device language is set to Japanese.
• Server lists are now always saved in full. Entries beyond the free limit are kept and marked rather than removed.
• Fixed: Pro features could briefly appear unavailable at launch while the App Store entitlement check was still in progress.

Requires iOS 26 or later.