Macro to change a date using the +/- keys.

I admittedly know very little in the way of Macros/VBA, but I hope this can be done by borrowing some your expertise.

I have set up a balance sheet for one of my less computer proficient friends. Overall, they love the setup, but they hate having to type in the date for every entry. Apparently, Quickbooks has an option through which you can use a + or a - to change the date up one day or down one day respectively.

My request is the following: I would like for Excel to automatically copy the date from the previous row once a new row is selected. Next, using this information as a basis, I would like the user to be able to press + or - to change the date.

I will attach a sample balance sheet as a reference.