For filling, combine dates, sugar, orange peel and orange juice in medium-sized saucepan. Cook over low heat, stirring occasionally until thickened. Cool. Stir in nutmeats. For base, sift together flour, soda and salt. Add oats and sugar; mix well. Stir in butter; mix until crumbly. Firmly press 2/3 of mixture into greased 8-inch square baking pan. Spread filling evenly over crumb base. Top with remaining crumb mixture; pack lightly. Bake in preheated moderate oven (350 F.) 30 to 35 minutes. Cool; cut in bars.