Making the Activity Start Date and Activity End Date fields non editable

Hi team,

We have a requirement wherein, we want to make the Activity Start Date and Activity End Date fields non editable at the layout level. These fields will be automatically updated from a backend script when an activity is created. But then, later on these fields must become non-editable at the layout level (not field level). Since it is a standard field, the property at field level is set to updatable and is not editable. But when we provide option to make them non editable at layout level, our configuration is not being saved and the field remains editable when we revisit the next time.