Sorry if this is a duplicate post, I was in the middle of typing my post and I hit something with my pinky and it disappeared.

I ahve a series of invoice values in columns a & b and the dates of those invoices in column c. I am trying to program a macro to total all invoice values by month & year, and put that data elsewhere so I can chart monthly billings. I tried SUMIF but did not have any luck getting it to work. Data is laid out:

Invoice value A Invoice value b Invoice date
$$$$ $$$$ mm/dd/yy

thanks