Currently in admin panel/listings we can add the 'date of creation' in the columns.

But the 'date of creation' is not editable. Is it possible to make this editable with the date picker?

As my website is more of a database I will be adding items all the way back to the year 1990 ish. So I wanted to change the 'date of creation' to the date that the item was released. Would changing the date of creation to say may 17th 1996 cause any issues in the script?

I know I could probs do this direct in the database but would be easier within the script