For the bread pudding: Preheat the oven to 350 degrees F. Spread the bread cubes on a large baking sheet and bake, stirring twice, 10 minutes. Let cool (leave the oven on).
Butter a 2-quart square baking dish. In a large bowl, whisk together the reduced-fat milk, granulated sugar, orange peel, cardamom and eggs. Add the dry bread cubes and dates; toss to coat the bread with the egg mixture.
Pour the egg mixture into the prepared baking dish and let sit for 10 minutes. Using a flat spatula, press the bread down into the egg mixture, then bake until a knife inserted near the center comes out clean, 45 to 50 minutes.
For the orange whiskey sauce: Meanwhile, in a medium saucepan, combine the milk and brown sugar. In a small bowl, combine the orange juice, cornstarch and 3 tablespoons whiskey and stir together with a fork until combined. Pour into the milk mixture in the pan, scraping the bowl to get all of the cornstarch. Bring to a boil over medium-high heat, stirring constantly. Turn down to medium-low and cook until thickened, 1 to 2 minutes. Remove from the heat and stir in the butter, salt and remaining 2 tablespoons of whiskey. Serve over the warm bread pudding.