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
pătĕfīo: fieri, v. patefacio.
pătĕfīō,¹² factus sum, fĭĕrī, pass. de patefacio.