Start date, Today's date, Cumulative days between the two

To subtract Today from Start the date has to be reformatted to a number. Ordinary humans (me) find it difficult to readily grasp the #'s meaning.

So does that then entail double columns for each date--one formatted as a date to understand visually the date and the other as a number for the calculation?

Also, if I enter the keyboard shortcut for Today's date, save and then reopen the sheet the next day will said Today's date be automatically updated? But here's the clinker, that Today's date shortcut entered a visual date--I need a Today's date that the math will work with?

Mark