Line a 9-in. pie plate with pastry; trim and flute edges. Line pastry shell with a double thickness of heavy-duty foil. Bake at 450° for 8 minutes. Remove foil; bake 5 minutes longer. Cool on a wire rack.
In a small saucepan, melt butter. Remove from the heat; whisk in the sugar, vinegar, cinnamon and nutmeg. Stir in the eggs, dates and pecans. Pour into crust.
Bake at 375° for 35-40 minutes or until set. Cool on a wire rack. Serve with whipped cream. Refrigerate leftovers.