BangleApps/apps/widadjust

Adjust Clock

Adjusts clock continually in the background to counter clock drift.

Usage

First you need to determine the clock drift of your watch in PPM (parts per million).

For example if you measure that your watch clock is too fast by 5 seconds in 24 hours, then PPM is 5 / (24*60*60) * 1000000 = 57.9.

Then set PPM in settings and this widget will continually adjust the clock by that amount.

Settings

See Basic logic below for more details.

• PPM x 10 - change PPM in steps of 10
• PPM x 1 - change PPM in steps of 1
• PPM x 0.1 - change PPM in steps of 0.1
• Update Interval - How often to update widget and clock error.
• Threshold - Threshold for adjusting clock. When clock error exceeds this threshold, clock is adjusted with setTime.
• Save State - If On clock error state is saved to file when widget exits, if needed. That is recommended and default setting. If Off clock error state is forgotten and reset to 0 whenever widget is restarted, for example when going to Launcher. This can cause significant inaccuracy especially with large Update Interval or Threshold.
• Debug Log - If On some debug information is logged to file widadjust.log.

Display

Widget shows clock error in milliseconds and PPM.

Basic logic

• When widget starts, clock error state is loaded from file widadjust.state.
• While widget is running, widget display and clock error is updated periodically (Update Interval) according to PPM.
• When clock error exceeds Threshold clock is adjusted with setTime.
• When widget exists, clock error state is saved to file widadjust.state if needed.

Services

Other apps/widgets can use WIDGETS.adjust.now() to request current adjusted time. To support also case where this widget isn't present, the following code can be used:

function adjustedNow() {
  return WIDGETS.adjust ? WIDGETS.adjust.now() : Date.now();
}

Acknowledgment

Uses Clock Settings icon by Icons8.