Can't seem to figure out why the following error occurs:
I asked you kind chaps for some help a while back, see http://www.ozgrid.com/forum/showthread.php?t=50041
The formula works wonderfully. Adding new donors is no problem whatsoever. However, if I change the 1st Month of a payment (eg, because someone has increased their donation, which'll kick in at a later date) then i get a #NUM! error in the formula.