Placed in 376.  Maran, Vit. Bas. xxxv., thinks that this letter is to be placed either in the last days of 375, if the Nativity was celebrated on December 25, or in the beginning of 376, if it followed after the Epiphany.  The Oriental usage up to the end of the fourth century, was to celebrate the Nativity and Baptism on January 6.  St. Chrysostom, in the homily on the birthday of our Saviour, delivered c. 386, speaks of the separation of the celebration of the Nativity from that of the Epiphany as comparatively recent.  cf. D.C.A., 1, pp. 361, 617.