Check precise NTP reference time at a glance. AtomicClock helps you set watches, wall clocks, cameras, and other devices, compare local time with UTC, and follow moments when every second matters.
Clear analog and digital time
AtomicClock displays current time from NTP servers that reference atomic clocks. Choose a predefined server or add your own, then view local or UTC time in a clean analog or digital clock.
Customize your reference clock
• Switch between 12-hour and 24-hour time
• Customize the time format
• Choose from multiple clock faces and hands
• Use a smooth, fluid second hand
• Add acoustic ticking or the Greenwich Time Signal
• Tap the screen to hide information and controls, freeze the display, or mute ticking
Details for precise time checks
View technical NTP information, including round-trip time and server stratum. Whether you are checking a timestamp, preparing a camera, aligning a wall clock, or setting a watch by hand, the seconds remain clear and easy to follow.
AtomicClock is free to use. AtomicClock Pro is available as a one-time purchase with no subscription. It unlocks your preferred clock face, hands, and font, removes ads, and includes upcoming Pro features.
AtomicClock displays NTP reference time for comparison and does not change your device’s system time. Results can vary with the selected server, network conditions, and device behavior.
I am a watch collector, main focus on Rolex as well as JLC, and several others I today picked up from my dealer a new steel Datejust, my focus is “functional “ rather than vintage or simply aesthetic hence my need for a good precise time app both to sync and also a diagnostic: time deviation. I’ve had several apps over the years 3 at least! After coming home from my Rolex dealer I wanted to get a solid sync for my fresh from box timepiece, both to set accurately but as a start point getting a feel of Calibre 3235 over next week. I looked at last app but it had some annoying issues. Hey I saw this and it was free! Downloaded SIMPLE TO custom set I gave it a more legible background for me put in wider hands and bolder hour markers. Easy peasy! I compared it to a G Shock that I recently calibrated from a good signal! It’s was SPOT ON AND I LOVE THE WAY YOU CAN CUSTOMIZE IT FOR YOUR USAGE! Having rambled !! Short summation it’s the easiest, set up, and can be as simple or give as much as one needs! THIS IS THE SINGLE BEST APP THIS WATCH GUY HAS EVER HAD THE PLEASURE TO HAVE USED! Thanks to the programmers this!
A top clock app
JJBarnone
I first started using this app in December of 2021 and use it multiple times a day on a daily basis. It helps to accurately set my timepieces and synchronize many gadgets that I work on. It’s great that you are able to set the clock face as simple or complex as you want, with an endless array of display and face settings. Thank you for making such a great app that’s easy to use and allows so many user options. All of the updates have been positive improvements - not that it’s lacking to begin with. This is how apps should be made.
Exactly what I need for accurate time
stuart bruce becker
I use this app to adjust time when we change the time in November and March. And periodically when I notice a clock is not perfectly set. I like each clock set to the exact time. Nice features. I’ve noticed a few people mention ads. It’s an ad at top that you can easily adjust to a very small size. It’s usually the width of a pencil. And the developer should make some money for their time and effort. Great app. Many nice features I appreciate.
Developer Response
Thanks for taking the time to write such a detailed review. I’m happy to hear the app helps you keep your clocks perfectly synced and that the features are useful for your routine. I also appreciate your understanding about the ads and the kind words about the work behind the app.
It works
Si Cantwell
I’m kind of a time nerd. Most clocks, iPhone included, give time to the minute. If you’re setting another clock, you can’t get it right to the second unless you wait for another new minute to turn over. With Atomic Clock, you can anticipate the new minute and set digital or analog clocks to the precise second. I find myself using it more often than I thought I would. (BTW, the iPhone clock is precise judging by this app, which is reassuring.)
• Improved app reliability and compatibility with latest platform components
• General performance and stability improvements
Version 3.6.24
The developer, Timo Partl, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
Identifiers
Data Linked to You
The following data may be collected and linked to your identity:
Location
Identifiers
Usage Data
Diagnostics
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
Diagnostics
Privacy practices may vary, for example, based on the features you use or your age. Learn More
The developer indicated that this app supports the following accessibility features. Learn More
Supported Features
VoiceOver
Larger Text
Dark Interface
Differentiate Without Color Alone
Sufficient Contrast
Reduced Motion
Information
Seller
Timo Partl
Size
17.9 MB
Category
Utilities
Compatibility
Requires iOS 15.0 or later.
iPhone Requires iOS 15.0 or later.
iPad Requires iPadOS 15.0 or later.
iPod touch Requires iOS 15.0 or later.
Mac Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
