I need to grab today's date and find out which month it falls into. For example, today's date, according to this calendar, falls in the fiscal month of August.
I need to calculate how many days there are left in each fiscal month. The answer here would be today's date (7/29 subtract 08/22) and that answer in a new column (24 days)
you need to build a (dimension) table that for each day says what the end (and start) of the fiscal month is. then JOIN that data to your transactions. after that, dateDiff is a piece of cake.