code: @Override
    public void triggered(org.quartz.core.Calendar calendar) {
  
      previousFireTime = nextFireTime;
      nextFireTime = getFireTimeAfter(nextFireTime);
  
      while (nextFireTime != null
          && calendar != null
          && !calendar.isTimeIncluded(nextFireTime.getTime())) {
        nextFireTime = getFireTimeAfter(nextFireTime);
      }
    }
docs: Called when the <code>{@link Scheduler}</code> has decided to 'fire' the trigger (execute the
  associated <code>Job</code>), in order to give the <code>Trigger</code> a chance to update
  itself for its next triggering (if any).
  
  @see #executionComplete(JobExecutionContext, JobExecutionException)