In a saucepan, combine the dates, sugar, water and butter. Simmer for 5 minutes, stirring occasionally, or until dates are softened. Remove from heat; stir in chocolate chips.
Beat eggs, milk and orange juice. Combine flour, baking soda and salt; add to date mixture alternately with orange juice mixture, mixing well after each addition. Stir in walnuts. Pour into a greased 15x10x1-in. baking pan.
Bake at 350° for 25-30 minutes or until a toothpick comes out clean. Cool. Combine confectioners' sugar, butter and orange zest; stir in milk until glaze reaches desired consistency. Spread over bars.