ClockSync ties your device to atomic time using NTP, offering both root and rootless modes for automatic or assisted manual synchronization. With configurable servers, precise timing options, and robust time-zone management, it’s a versatile tool for keeping clocks accurate across networks and geographies.
Pros & Cons
Supports both root and rootless operation for flexible usage
Configurable NTP/SNTP servers and timeouts for reliable syncing
High precision in root mode (~1-20 ms) and practical rootless timing
Automatic time zone detection and Olson tz database-based zone management
Multiple display options (12/24 hour, date display, color schemes)
Optional haptic feedback and sync notifications for UX feedback
Root is required for full automatic synchronization, which may limit non-root users.
Lacks home screen widgets (no dedicated clock widgets) for quick access.
About ClockSync
ClockSync was a tools app developed by Sergey Baranov. It was removed from Google Play Dec 4, 2019 and is no longer available for download.
Download Statistics
ClockSync had been downloaded 2.2 million times before it became unavailable.
User Ratings
ClockSync was rated 4.68 out of 5 stars, based on 58 thousand ratings.
App Information
ClockSync was free to download. The APK download size was 246.10 kB. The last available version was 1.2.6. The last update was on March 28, 2016.
Technical Requirements
ClockSync required Android 1.5+ or higher. The app had a content rating of Everyone. The app had been available on Google Play May 2010.
Description
☆ ROOT is REQUIRED for automatic synchronization ☆
ClockSync synchronizes device system clock with atomic time from Internet via NTP (Network Time Protocol). Useful if provider doesn't support NITZ, sends incorrect time or if your device/ROM has heavy clock drift.
There are 2 modes: automatic for root users and assisted manual mode for users without root (rootless mode).
Rootless mode features: - automatic atomic time retrieval with configurable interval - notification when offset exceeds user set threshold - assisted manual synchronization with the hint what time/date to set - precision between 1 and 30 seconds (because Android doesn't allow to set seconds) - 1 second precision if your device resets seconds on Set (most Samsung and some HTC devices) - Greenwich Time Signal assisted sync if device resets seconds
Root mode features: - automatic sync with configurable interval - accuracy is ~1-20ms depending on your connection and NTP server - statistics (average drift per day, total time corrected)
Root is required because of Android security restrictions (user apps cannot set time).
Other features: - customizable NTP/SNTP server and timeout - displays current date or time since last sync - NTP server details dialog - 3 color schemes (dark, light, default) - 12-hour or 24-hour clock format - time zone detection and adjustment based on geo location - system time zone override with custom offset - time zone management based on latest Olson tz database (zoneinfo) - optional haptic feedback and sync notification - clean and easy to use interface (tap screen values or use menu)
Don't have root? See http://bit.ly/phoneroot for the detailed instructions.
Don't want or can't root your device? You can still use ClockSync as your precise time source to adjust your watch or other clocks, or to verify how accurate your cell time is, or set time manually in rootless mode.
Move to SD is disabled because automatic synchronization (timers) will not work when app is moved, also app size is very small and since not all files are moved to SD in any case, it would not save you more than 50Kb.
If you get wrong time after synchronization, your phone time zone data is out of date, use http://bit.ly/tzupdate to fix it.
Issues, questions or suggestions? Please e-mail me, developers have no way to respond to Market comments. I reply to every e-mail within one day maximum (usually instantly).
See http://bit.ly/clocksync for more information. Google+ Community: http://bit.ly/cs-plus
Permissions explained for paranoid users: - RECEIVE_BOOT_COMPLETED: used only for "Sync on boot" option - VIBRATE: optional haptic feedback on tap and sync - INTERNET: to get time from NTP servers, to get time zone from web services - WAKE_LOCK: to perform background synchronization without being killed in the middle by the OS - ACCESS_NETWORK_STATE: to sync only when network is available - ACCESS_FINE_LOCATION: to get best location for time zone from location feature when GPS is on - ACCESS_COARSE_LOCATION: if GPS is off, network location is used - SET_TIME_ZONE: to automatically set time zone depending on location or for manual override - SYSTEM_ALERT_WINDOW: new permission since 1.1.5, used for transparent overlay in rootless mode to show countdown updated every second - ACCESS_SUPERUSER: for compatibility with SuperSU and Superuser applications, see http://bit.ly/su-permission
Recent changes: - support for Android 6 Marshmallow (if you get incorrect time after sync, remove 'date' applet from BusyBox) - fixed old icon for some resolutions
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★★★★★
I always use this app to set all the clocks around my house to the accurate time. It is especially helpful after power outages and seasonal time changes when all the clocks need to be re-set.
★★★★★
Works great. Has all the features I need. Have you ever considered adding a widget feature though?
★★☆☆☆
Worhless app. Wont connect to NTP server.
★★☆☆☆
Doesn't seem to successfully update the system clock with magisk, although it work when I used supersu previously.
★★☆☆☆
Assisted manual mode no longer works on Android 10 - assist window persists (EXCEPT during time setting, ironically) and cannot be dismissed! Please fix for Android 10!
Technologies used by ClockSync
10 permissions
Subscribe to see full permission and library details
Trust & Safety: Permissions include location (ACCESS_COARSE_LOCATION, ACCESS_FINE_LOCATION) to determine time zone, network state, and system/network access; SYSTEM_ALERT_WINDOW is used for a countdown overlay in rootless mode; RECEIVE_BOOT_COMPLETED, WAKE_LOCK, and INTERNET enable background syncing and server access; SUPERUSER/ROOT access is included for compatibility with rooted devices. These permissions align with the app’s time synchronization and timezone features, with explicit explanations in the permissions section.
Each subscription will automatically renew 3 days before the expiration date for
the same time period. Subscriptions can be cancelled at any time before the renewal.
