Cron build periodically setup

I’d like to run a monthly build, every 1st Monday at 11:45pm. The cron expression “45 23 ? * MON#1” should work. But, it doesn’t. What’s the correct expression for Jenkins? Thanks.

I used range like 45 23 2-8 * 1

I thought this would work for the 2nd Saturday, but it didn’t function as expected:
H 4 8-14,21-28 * 6

I had to split this like so:
H 4 8 * 6
H 4 9 * 6
H 4 10 * 6
H 4 11 * 6
H 4 12 * 6
H 4 13 * 6
H 4 14 * 6

You might want to re-check if your schedule actually works.