I added a column to calculate the date based on two other existing columns. When I view an item in my list, the other two columns show up but my calculated column does not show. I do see it when I view the entire list, just can't see it when I view individual items in the list.

Hi,Can you check your view settings, if this calculated column is selected?Thanks,Skancharla

When you say you "view an item" in the list, do you mean you are viewing the detail (dispform.aspx) for the item? If so, typically a new calculated column will show up, so do you know if the dispform.aspx page has been customized?