Need to summarised order/invoice data by financial period. This Financial
Year we have 12 Financial Periods each involving the following number of
weeks: P1 = 4, P2 = 4, P3=5, P4=4, P5=4, P6=5, P7=4, P8=4, P9=5, P10=4,
P11=4, P12=5. In MS Excel is there a way of Grouping Dates to reflect these
varying lenght periods so we can use the Group in Pivot Tables?