When scheduling a recurrence item on Outlook Calendar, there only 2 options:
1- Certain date of the month; i.e. 30th of every month
2- last {Day} of the month; i.e. Last Friday of every month

Both of these options do not allow you to set a reminder on the last WORKING day of the month.

If you choose number one, the occurrence may fall on a Saturday or Sunday and it is not helpful if you are not working on those days.
If you choose number 2, the occurrence may fall few days before the end of the month.

I suggest adding an option to choose the reoccurrence on the the Last Working Day of every month to help people with their data reporting reminders and other activities.

Thanks,
Amal