How does quartz track the time

How does quartz track the time ? Is it a continuous timer running in background or does it somehow uses the OS scheduler or is it somet开发者_StackOverflow社区hing else ?

Which class actually holds this feature ?

Thanks.

As far as I digged into Quartz source code, I found (at least for StdScheduler implementation which is proxy of QuartzScheduler) that its scheduling thread QuartzSchedulingThread uses System.currentTimeMillis() for prediction of the next job trigger run.

Please look inside QuartzSchedulerThread.java .