λευκόπωλος
From LSJ
ἐν δὲ μηνὸς πρῶτον τύχεν ἆμαρ → it chanced to be on the first of the month, that day fell on the first of the month
English (LSJ)
ον,
A with white horses, ἡμέρα A.Pers.386, S.Aj.673; τέθριππον Plu.Cam.7; epith. of the Dioscuri (cf. λεύκιππος), Pi.P.1.66; at Thebes also of Amphion and Zethus, E.HF29; θεοί Id.Ph. 606.