Round Millisecond Clock shows the current device time inside an outer seconds ring and an inner fractional-time ring. The center displays hours and minutes, then seconds with one decimal digit. You can also show the date and day of the week, choose a color theme and adjust the displayed time.
Read the rings and center digits
| Display | How to read it | What to check |
|---|---|---|
| Hours and minutes | Read the current time, such as 22:04. | Choose 24-hour time or 12-hour time with AM/PM. |
| Center seconds | 20.5 means 20 seconds and 0.5 seconds into the minute. | The single decimal digit gives a 0.1-second display. |
| Outer ring | Shows seconds in 60 steps. | At the zero-second boundary, the ring appears full. |
| Inner ring | Shows the fraction of a second in 100 steps of 10ms. | A fraction of 0–9ms appears as a full ring. |
| Last five seconds | The center seconds turn red at 55–59 seconds of each minute. | The whole ring does not turn red, and this is not a completion alert. |
Although the app name mentions milliseconds, the center does not show three decimal digits such as 20.500. A 10ms ring step also does not establish 1ms accuracy or guarantee that every screen update occurs exactly 10ms apart. The app reads device time; the Dart periodic timer documentation explains that callback intervals can vary. Use an independently validated timing method for sports adjudication, scientific experiments, reaction-time measurement or video-frame synchronization.
Choose your display in Settings
Tap the gear at the top right of the clock to open Settings.
- Choose a green, blue or orange palette under Theme.
- Under Date Format, choose US(MM/DD/YYYY), EU(DD/MM/YYYY), ISO(YYYY/MM/DD) or Short(MM/DD). The app's ISO label uses slashes for its display format.
- Use Show Seconds Ring and Show Milliseconds Ring independently. Turning both rings off leaves the center seconds visible.
- Use Show Day of Week, Show Date and Use 24-hour Format to choose the other information. Turning off 24-hour format adds AM/PM.
- Use the back arrow at the top left to return to the clock. Changes are saved when you leave Settings, then reloaded by the clock. An ad may appear when settings change.
Adjust the displayed time with Time Offset
If you want the displayed time slightly ahead of or behind another clock, find Time Offset near the bottom of Settings. The +0.1s and -0.1s buttons move it by 100ms; +1s and -1s move it by one second. The controls are limited to -10 to +10 seconds. Tap the displayed offset value to reset it to zero, then return with the back arrow to save.
A positive offset displays a later time than the device clock; a negative offset displays an earlier one. Crossing midnight also affects the displayed date and weekday. This manually shifts the app's display. It does not change the phone's system clock or perform automatic server synchronization or calibration.
Use it as a desk clock
The app requests that the screen stay awake when it starts. Check the result on your device and operating system, and close the app or lock the screen when finished. The circular area adapts to the available width and height, but font scaling and layout on your installed device still need checking.
The current app is centered on displaying current time. For Start/Pause interval timing or a countdown you enter yourself, see ms clock's clock, timer and stopwatch guide. This circular display is not an automatic experiment logger or proof of precise synchronization between devices.
Download and get support
Use the download section below for Google Play or the App Store. The public Apple version is 1.1.2 and its release notes mention the Time Offset addition. This guide compares current local source with public store information; it does not verify an installed binary or measurement accuracy on a device.
For display or settings problems, contact support with your device, operating system, app version and steps to reproduce the issue. See the app privacy policy and the current store disclosures for advertising and privacy information.