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
χρηστός, εὐκρινής, εὔτακτος, ἥμερος, ἅμερος, ἐμμελής, συστηματικός