This is really easy with formulas. If you type in =Today() into a cell you'll get today's date. Add a plus one or minus one (or any number) to get tomorrow's or yesterday's date. Tomorrow will be =Today()+1 and yesterday will be =Today()-1
You can use TODAY() function. So to compare a date BEFORE today's date, type =A1-less-than-TODAY() Once you have that set, just look for value TRUE. Similarly greater-than TODAY() for future.
