It is certain the Catechetical Lectures i.–xviii. were all delivered in these six weeks, being preceded by the Procatechesis, which was addressed to the candidates before the whole congregation at the public Service on Sunday (§ 4).  In the same context Cyril says, “Thou hast forty days for repentance,” and again in Cat i. § 5, “Hast thou not forty days to be free for thine own soul’s sake?”  It thus appears probable that the first of the eighteen (Catechetical Lectures was delivered on the Monday of the first week of the Fast, the forty days being completed on the night preceding the Great Sabbath, that is to say, the night of Good Friday, when the fast was brought to an end at a late hour.