Sounds like the fields used in your script are not the fields you are editing to enter these dates.
Check the full field references for the fields where you enter the dates and compare them to that used in your script.
The full field reference can be seen in "display data from" in the Inspector as well as in your script steps and data viewer. A full field reference takes the form of TableOccurrenceName::FieldName. My best guess is that you have two fields with the same name, but defined in different tables and thus your script refers to a field from one table while the fields you are editing are defined in a different table.
Thank you for the guidance. That did the trick.