[Solved] Convert from daily to monthly income summary

Hi,

I have an income report that lists products and the total that they earn each day. There are about 50 products.

I need to know how much each product earns each month.

I can sort the products so that they are grouped together but then I have 30 days of sales to add up.

How can I calculate each product's income by month?

To clarify, my table presently show:

PRODUCT | DATE | $ INCOME

widgets | 1 jan | 12.31
widgets | 2 jan | 11.22
widgets | 3 jan | 14.88
etc for 31 days then
spraglets | 1 jan | 2.31
spraglets | 2 jan | 1.22
spraglets | 3 jan | 4.78
etc for 31 days then
48 more products.

I'd be grateful to know.