Adding one day to a date

Hello,
I have a spreadsheet that i use for planning truck maintenace, I am trying to work out how to have 2 buttons that i can assign 2 macrows too, one to add one day to a date in a cel, and one the subtracts a day from the same cel. thiswill make it easier to change the date in the cel up or down with out having to click in the cel and changing it.