εἰς τὸ δεκαπλάσιον

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

Source

Dutch (Woordenboekgrieks.nl)

tot in het tienvoudige Plut. CMa 18.2.