Thank you this was very helpful, but it is not working for the week day number in my Model (The Cumulate Function). Please advice.
Also I started Referencing my Line Items "Day of the Week Number" and "Month Number" to the "Start Day" Line Item. So those line items will be based off of "Start Day", but I would like as a second option to put a Boolean Line Item in that if you check that Boolean Line Item then you can choose a "Reference Date" for the Line Items "Day of the Week Number" and "Month Number" to be based on, how would I do this? If that does not make sense let me know. Screen Shots Attached.