OK... This one made me see variables in my sleep. Thanks Gamejag for the great base.
Max
[Edit: For those looking for the current files:
For those experienced that can handle diff comparisons, I have the differences between stock 5.5.1 threads files and the calendar modification (v2.2).
diff.zip(stock 5.5.1 on the left and modifications on the right)
For us mere mortals, here is a more understandable instruction set:
calendar_2_2.zip