@June7, you say it's unnecessary to save the DueDate automatically to the table because it can be calculated when necessary, but the premise of your solution to my initial problem was relying on the user as little as possible; why would I want to have the user calculate the due date every time they calibrate a tool if the main concern is decreasing user reliability?
Using a calculated field type seems to be working perfectly! Thank you for introducing me to that feature, I did not know it existed. I appreciate all of your help!