Error when sorting dates in a Enum column type

Good day to all,

I have a form with a date field of ENUM type data comes from a slice. When using ORDERBY to sort the dates ascending, get an INVALID DATE on the form. If only a select is used it works but the dates are not in order. From another post @Aleksi suggested to use TEXT as the base type for the ENUM. When I changed it to text got a long date which then gave error when saving to the DATABASE.

What is need is a list of unique dates sorted in descending order, how can that be acomplished?

Attached screen shots.