In a bowl, whisk together egg yolks and honey until well blended, then whisk in cream, milk, and vanilla. Pour mixture through a fine strainer into another bowl; discard residue.
Pour into four ramekins (3/4-cup capacity). Set in a 9- by 13-inch pan (with at least 2-in. sides). Set pan on rack in a 325° oven. Pour boiling water around ramekins almost to top of custards. Cover pan with foil, turning back 1 inch at each corner to release steam.
Bake until custards jiggle only slightly in the center when gently shaken, 50 to 55 minutes. With a wide spatula, lift dishes from water and transfer to a rack. Let custards cool completely, then cover and chill until cold, about 2 hours, or up to 2 days. Garnish with slivered dates and lemon peel.