Premium
Download AtomicClock: NTP Clock 2.1.20 APK
Target: Android 17 (API 37)
480, 640dpi
What's new in AtomicClock: NTP Clock 2.1.20
• 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
About AtomicClock: NTP Clock 2.1.20
Need the exact time to set a watch, set a wall clock, compare UTC, or catch a moment where seconds matter? AtomicClock displays precise NTP time from internet time servers that reference atomic clocks.
Premium
Use AtomicClock as a clean NTP clock, atomic clock app, UTC clock, precision clock, or reference clock. It combines a readable analog clock and digital clock with technical network time details when you need them.
Why people use AtomicClock
• Check exact current time from selectable NTP time servers
• Manually set watches, wall clocks, cameras, radios, and other devices
• Compare local time with UTC, GMT, and Greenwich Time Signal
• Keep a seconds clock open for New Year's Eve, birthdays, photography, astronomy, radio, IT, engineering, and hobbies
• Use a clear clock display on your phone or tablet
NTP time and server control
• Choose from predefined time servers or add a custom NTP time server
• View technical NTP information such as round-trip time and stratum
• Switch between local time and UTC
• Use 12-hour or 24-hour time and customize the time format
• Check network time without changing your Android system clock
Clock display and sounds
• Analog clock and digital clock views
• Multiple clock faces and clock hands
• Smooth second hand for an easy-to-read seconds display
• Optional acoustic ticking sounds
• Greenwich Time Signal for classic reference timing
• Tap actions to hide info/menu, freeze the screen, or mute ticking
Clock widget
• Add a customizable home screen clock widget with time and date
• AtomicClock Pro includes many widget customization options
• For technical and battery reasons, the clock widget uses Android system time; open the app for NTP reference time from selected servers
Free and Pro
AtomicClock is free to use. AtomicClock Pro is a one-time purchase with no subscription and unlocks preferred clock face, clock hand, clock font, ad removal, all tap actions, picture-in-picture mode, and upcoming Pro features.
If you need precise time, atomic time, an NTP clock, a UTC clock, a GMT clock, an analog clock, or a simple reference clock for setting devices manually, AtomicClock keeps it clear and focused.
AtomicClock: NTP Clock 2.1.20 variants
This release comes in several variants (we currently have 2). Consult our handy FAQ to see which download is right for you.
Version:2.1.21(140) for Android 10+ (Q, API 29)
Uploaded:June 30, 2026 at 7:44PM UTC
File size:4.33 MB
Downloads:4
Version:2.1.20(139) for Android 10+ (Q, API 29)
Uploaded:June 16, 2026 at 9:22AM UTC
File size:4.37 MB
Downloads:13
Version:2.1.19(138) for Android 10+ (Q, API 29)
Uploaded:June 15, 2026 at 1:32PM UTC
File size:4.37 MB
Downloads:8
Version:2.1.18(137) for Android 10+ (Q, API 29)
Uploaded:April 16, 2026 at 11:59PM UTC
File size:4.20 MB
Downloads:29
Version:2.1.17(136) for Android 10+ (Q, API 29)
Uploaded:February 16, 2026 at 11:56AM UTC
File size:3.85 MB
Downloads:14
Version:2.1.21
Uploaded:July 2, 2026 at 7:23AM UTC
File size:7.69 MB
Downloads:16
Version:2.1.20
Uploaded:June 16, 2026 at 9:23AM UTC
File size:4.49 MB
Downloads:26
Version:2.1.19
Uploaded:June 15, 2026 at 1:32PM UTC
File size:4.49 MB
Downloads:12
Version:2.1.18
Uploaded:April 16, 2026 at 11:59PM UTC
File size:7.45 MB
Downloads:60
Version:2.1.17
Uploaded:April 15, 2026 at 5:30PM UTC
File size:6.98 MB
Downloads:39
Version:2.1.16
Uploaded:December 21, 2025 at 5:51AM UTC
File size:4.67 MB
Downloads:52
Version:2.1.15
Uploaded:October 17, 2025 at 7:48AM UTC
File size:4.55 MB
Downloads:40
Version:2.1.14
Uploaded:August 8, 2025 at 9:17AM UTC
File size:7.16 MB
Downloads:60
Version:2.1.13
Uploaded:August 1, 2025 at 6:06PM UTC
File size:7.14 MB
Downloads:33
Version:2.1.12
Uploaded:July 6, 2025 at 7:43PM UTC
File size:6.95 MB
Downloads:31
