Working with dates makes my head hurt
What format does your system use? Mine uses dd/MM/yyyy
MC always attempts to follow the system date format.
I got what you want, but it was a two step process...
I used the "Fill Properties" tool to bring the whole date string into a string defined field. For my test, I used the [Comment] field.
I then selected the file, and, in the tag window, edit the date field by putting this into the date field and pressing <Enter>...
=mid([comment],2,2)//mid([comment],0,2)//mid([comment],4,4)
[Comment] contained 02202024
After entering the expression above into the [Date] field, [Date] became 20/02/2024
Note that I switched the day and month values so that they matched my system date format.
Test with one file first until you're happy, then you can select multiple files and do them all at once.
After the dates are correct, you can safely delete the contents of the [Comment] field.
There's a strong possibility that there's a more direct way to achieve this, but until one comes along, this should hopefully get you going.
Good luck.