CalendarIntervalSchedule is firing non-stop for 10 mins on the day that DST begins (and we lose an hour).

[mwithum-paylocity]

Consider a Calendar Interval Schedule that:

• Runs every other Sunday at 2:01 AM Central
• Starts on 2/25/2024 2:01 AM
• And lines up to run at 2:01 AM on 3/10/2024
  • but that is the day that the clock rolls forward, so 2:01 AM doesn't exist
• Quartz will (on the previous fire in 2/25/2024) correctly set the next fire time to 3/10/2024 3:00 AM -- the earliest time that exists after it was "supposed to fire"

So far all seems correct. However, when 3/10/2024 3:00 AM comes around - the trigger fires non-stop for 10 mins exactly. It is almost like the next fire time never calculates a good time after 3/10/2024 3:00 AM. We had one trigger fire > 30k times.

I can repro this in the TriggerUtils.ComputeFireTimes method as well. I've attached an annotated sample where TriggerUtils.ComputeFireTimes is doing exactly what I am seeing when Quartz do - it gets stuck on 3/10/2024 3:00 AM.

QuartzDstRepro.zip

If you open that SLN and run it, you will see where it fails and the annotations will describe the problem.

Thanks in advance for any help!

[mwithum-paylocity]

I moved this to a bug report: #2349