due date

Question

hi all,

i am trying to find code that will help me recieve a warning when it is 2 or 3 or even 4 days to my due date of next purchase.

in my data base i have got a column called date of next purchase and this is the date i want to use so that i can select a product that is due 2 or 3 or 5 days before the due date in the data base.

i can select a product that is due by selecting all products where due date like datetime.now ,but i need to recieve the warning starting 2 days to the due date.
i hope i have not confused you in any way.

thanks.