static long timeJumpDetector_lastTimeJump; // in sys time
static long timeJumpDetector_lastTimeJumpLength;
sbool timeJumpDetector_verbose;
static L timeJumpDetector_onTimeJump = synchroList();
static int timeJumpDetector_minJump = 5000;

static void timeJumpDetector() {
  doEvery(1000, new Runnable {
    long diff = now()-sysNow();
    long lastSysNow = sysNow();
    
    public void run() {
      long sysNow = sysNow();
      long newDiff = now()-sysNow;
      long d = newDiff-diff;
      if (timeJumpDetector_verbose)
        print("timeJumpDetector: sysNow=" + sysNow + ", diff=" + newDiff);
      if (abs(d) <= timeJumpDetector_minJump && /*isWindows() &&*/ sysNow-lastSysNow >= 10000)
        d = sysNow-lastSysNow-10000;
      if (abs(d) > timeJumpDetector_minJump) {
        diff = now()-sysNow();
        timeJumpDetector_lastTimeJump = sysNow();
        timeJumpDetector_lastTimeJumpLength = d;
        printAndProgramLog(ymd_hms() + ": Time jump occurred! (" + formatDouble(toSeconds(d), 1) + " seconds)");
        if (nempty(timeJumpDetector_onTimeJump)) thread {
          pcallFAll(concurrentlyIterateList(timeJumpDetector_onTimeJump));
        }
      }
      diff = newDiff;
      lastSysNow = sysNow;
    }
  });
}

Began life as a copy of #1015617