Quote Originally Posted by clayv
Try (assuming dates are in A1:A10):

=SUM(IF(FREQUENCY(VALUE(MONTH(A1:A10)&YEAR(A1:A10)),VALUE(MONTH(A1:A10)&YEAR(A1:A10)))>0,1))

- Clay
Excel Help
This formula works perfectly. I extended the second row value to 1000 so that I can copy and paste large columns in from Access. when I delete the columns though, the formula changes because it's confused. The first time it switched to 841 (I think because I scrolled down that low but I don't remember). I don't know if there's a way I can keep the formula the same. any ideas? anyone know why this happens?