code: public static void set24HourTimeFormat(boolean use24HourTimeFormat) {
      Settings.System.putString(RuntimeEnvironment.application.getContentResolver(), Settings.System.TIME_12_24, use24HourTimeFormat ? "24" : "12");
    }
docs: Sets the value of the {@link Settings.System#TIME_12_24} setting.
  
  @param use24HourTimeFormat new status for the time setting