Fix Database update on time based submission

Have a form that is busy with multiple types of selections. One section has a dropdown of 5 boxes that are all time based and on submit, those 5 selections get posted to the same database table in a single row. Since each dropdown is time based, meaning at a certain time, the dropdown will become read only and they cannot either select an option or update their option for that particular dropdown, I need to be able to update the other active dropdowns without affecting the read only one(s). I have tried to delete and insert on each submission, but the select box(es) that have passed their allotted time will then wipe out their selection and only post the active selections. I have tried the same for update instead of delete and insert and cannot get that working either. I had this working in a previous version of the program that I was using and tried to mimic that process but it is above my skill level.