Preheat the oven to 400 degrees F (200 degrees C). Grease or line 10 cups of a muffin tin.
Whisk flour, sugar, baking powder, salt, and baking soda together in a bowl. Add dates, separating the pieces as you drop them into the flour mixture. Mix to coat.
Whisk buttermilk, egg, and butter together in a small bowl. Fold buttermilk mixture into flour mixture until just combined.
Spoon batter into prepared muffin tin.
Bake in the preheated oven until a toothpick inserted in the largest muffin comes out clean, about 15 minutes.
