What I'm trying to do is get Excel to insert a set of months under year headings with two columns of data beside them (invoice no. and date of payment) based on the number of payment installments and a starting date I enter into a cell. For example... No. of installments: 8 Starting date: 1st July 2007 ...would create the output... 2007 July August September October November December 2008 January February The two columns next to the month entries can remain blank as they will be filled in by hand on the printouts, though I'd like horizontal lines to appear in the cells to write above. Any ideas?