AtomicClock: Exact NTP Time

Contains adsIn-app purchases
18.6K reviews
Content rating
PEGI 3
500K+
Downloads
Content rating
PEGI 3
Digital Purchases
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About this app

Need the exact time to set a watch, align a wall clock, compare UTC, or catch a moment where seconds matter? AtomicClock shows precise reference time from NTP time servers in a clear analog or digital clock.

NTP servers provide network time referenced to atomic clocks. Choose a predefined or custom time server, then view local time or a UTC clock in 12-hour or 24-hour format. Use AtomicClock as an NTP clock, precision clock, reference clock, or seconds clock for manual time checks.

Practical ways to use AtomicClock

• Set a watch, wall clock, camera, or other device manually
• Compare local time with UTC
• Check precise time before an event or scheduled task
• Keep a clear clock visible while you work using picture-in-picture with Pro

Clock display and signal options

• Analog clock and digital clock views
• Custom time formats, clock faces, hands, and fonts
• Smooth, fluid second-hand movement
• Optional acoustic ticking sounds
• Greenwich Time Signal
• Home screen clock widget with time and date
• Tap actions to hide information, freeze the display, or mute ticking

For technical NTP checks, view details such as the selected time server, round-trip time, and stratum. Accuracy depends on the server, network conditions, and device behavior.

AtomicClock is designed for reference time and manual clock sync. It does not automatically change device system time. The home screen widget uses system time for technical and battery reasons.

AtomicClock is free to use. AtomicClock Pro adds preferred clock styles and fonts, many widget customization options, all tap actions, picture-in-picture, and ad removal. Pro is a one-time purchase through your Google Play account with no subscription.
Precise atomic time — UTC clock, Greenwich Time Signal and clock widget
Updated on
Aug 6, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • This app may share these data types with third parties
    Location, App activity and 2 others
  • This app may collect these data types
    Location, App activity and 2 others
  • Data is encrypted in transit
  • Data can’t be deleted

Ratings and reviews

17.2K reviews
Ezra b
July 1, 2026
After the last upgrade, I can't get the widget to have white font and a black background. Something changed. I want the wigets backgroud to be black, and the font white like it was before the upgrade. After the upgrade the backgroud turned white and the font black, i tryed to use the settings of the wiget with no success after upgrade number 2, fixed thank you, much success!
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Timo Partl
July 1, 2026
Glad this is fixed now. Thanks for the updated review. Enjoy the app!
Jacob Thrym
July 4, 2026
I've been using this app for years and it's always been consistently accurate and functional, I use it for zeroing my watches and clocks and to see how much certain devices have wondered off zero absolutely would recommend for any Horology enthusiasts
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Michael “MTR” Resch
July 22, 2026
Great app for setting the time on an analog watch. I use it all the time to set my Rolex to the second. Also works great using Microsoft's Phone App. Extremely clear display and easy to use.
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What’s new

• Redesigned the color picker for app and widget colors, with presets, a color wheel, and brightness control
• Pro: widget backgrounds can now be customized with color and opacity, and default widget colors follow your Android theme better
• Settings now use clearer icons to make customization options easier to scan
• Custom NTP servers now support host:port entries and better validation before saving