I just had a look at your formulas: the if conditions hidden in the min/max operators are pretty gorgeous. My hunch had been to start on the last day of the month and then subtract 1 or 2 to account for Saturday and Sunday using ITE columns, but I had no idea how to identify week days for the ITE conditions. Anyway the min/max operators are just so much more elegant.
The only thing that bothers me – and I’ll use this to put myself to sleep, it’ll work like a charm – is the lack of symmetry between +min,6 and -max,2. (For our practical purposes it works fine of course.)
Thanks for this!