四分律刪補隨機羯磨 1.415

1.415

(Both the Samantapāsādikā and the Vinaya root text say, "After conferring the upasampadā, the upādhyāya, ācārya, and others should record the season—spring, summer, or winter—the month, the day, down to the measuring of the shadow, and other details of the time of conferring the upasampadā.")