C# timer that fires every X seconds, but stays in synch with real time (i.e. with no drift)

Question

Is there a .NET Timer available in C# that can ensure there is no "drift" in between events? That is, if you set the timer to go off every X seconds, that after days of operating it won't drift, i.e. to ensure that approach number of X seconds events in a day remains in synch with what it should be?

If not, is there a well known code example that would wrap a Timer function in C# to do this?

Answer 1

I'm assuming you have tried something already, and that it drifts.

If you want something to fire at say every 5 seconds from the hour (5,10,15,20..), you could set your timer to fire once, then in your callback, reset the timer to fire at DateTime.Now + number of seconds to the next 5 second interval.

This would prevent any drifting as long as your clock is correct.

Something like this

System.Timers.Timer timer = new Timer();

void Init()
{
    timer.Elapsed += timer_Elapsed;
    int wait = 5 - (DateTime.Now.Second % 5);
    timer.Interval = wait*1000;
    timer.Start();
}


void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
    timer.Stop();
    int wait = DateTime.Now.Second % 5;
    timer.Interval = wait * 1000;
    timer.Start();
}