Preheat oven to 400°. Grease 2 rimmed baking sheets.
In a large bowl, whisk together flour, sugar, cream of tartar, baking soda, and salt. Using a pastry blender or 2 forks, cut in butter until it resembles fine breadcrumbs. Add dates, tossing lightly.
Beat 2 eggs slightly and add to mixture. Stir with a fork until the mixture forms a ball and leaves sides of bowl.
On a lightly floured board, roll dough to a ½-inch thickness. Using a 2-inch round cutter, cut as many scones as possible from dough, rerolling scraps once. Place on prepared baking sheets, spacing 2 inches apart.
Slightly beat remaining 1 egg, and brush on tops of scones.
Bake until golden brown, approximately 15 minutes.
Serve with Devonshire cream and jam, if desired.
Recipe by TeaTime Magazine at https://teatimemagazine.com/can-you-crack-the-case-in-carol-j-perrys-see-something/