Timer with slow system clock

Question

I have a timer that performs scheduled events at a fixed rate. If the system clock is slow, is it possible that the associated TimerTask will stop running? Is there anything else that may be unexpectedly halting the execution of the TimerTask? Thanks.

Answer 1

I have a server clock that I'd like to emulate on the client, by only obtaining the server time a few times per hour after initialization and relying on a client TimerTask to keep pace. Sometimes, a client's clock is slow due to a bad battery, etc. Occasionally, a client reports that their clock has either frozen or fallen off the pace by several seconds, even with a sound system clock. The code looks as follows:
private final TimerTask heartbeatTask = new TimerTask() {
        public void run() {
            synchronized (heartbeatListeners) {
                for (Iterator it = heartbeatListeners.iterator(); it.hasNext();) {
                    HeartbeatListener listener = (HeartbeatListener) it.next();
                    try {
                        listener.tick();
                    } catch(Exception e) {
                        e.printStackTrace();
            synchronized (serverTimeLock) {
                serverTime += 1000;
public init(...) {
     heartbeatTimer.scheduleAtFixedRate(heartbeatTask, 0, 1000);
}