Luke 22:15 (V)which Jerome explains: Wishing to put an end to the feast of the flesh and, through the passing shadow of the Pasch to restore the truth, fulfilling the law as He said:
Hieronymus, In Matheum 4:26.2 (CCSL 77: 245)I have not come to abolish the law but to fulfil it,
Matt. 5:17 (V)that is to augment it. Whence, coming to the Passion, fulfilling the Old Covenant and beginning the New, on Thursday, the fourteenth moon of the First Month (which is called Nisan amongst the Hebrews, Spantoriacos amongst the Macedonians, Parmothi amongst the Egyptians and amongst the Latins occupies sometimes part of March, sometimes part of April) as the evening proceeded, having taken
p.67bread, He gave thanks, blessed it, broke it, and gave it to His disciples, saying: This is My Body,
Consecration riteetc. Also: This chalice is the New Covenant in My Blood.
1 Cor. 11:25But when it was morning [(namely Friday)] all the chief priests took council.
Matt. 27:1 (V)On the next day however, [that is on the Sabbath, the fifteenth moon,] the chief priests gathered and set a guard on the sepulchre.
Matt. 27:62 and 66 (V)On the first day of the week,
Luke 24:1; John 20:1on the sixteenth moon, the bonds of hell having been loosed,
Acts 2:24He rose from the dead. After eight days,[however (that is the twenty-third moon)] He came and He stood among [the disciples and He showed His hands and feet and side, and said:] Peace be with you.
John 20:26-27However, on the fortieth day after the resurrection (namely from the sixteenth moon, not from the fourteenth) He led [his disciples] out to Bethany and, raising His hands, He blessed them
Luke 24:50-51and was raised up to heaven. And when the fiftieth day was completed (namely from the resurrection on the sixteenth moon, not from the passion on the fourteenth) the Holy Spirit rested upon each
Acts 2:3-4of the apostles as fire. Hence the entire church of the East has reverently allotted three weeks for the three most holy feasts of Our Lord Jesus Christ, that is [a week] to the Passion, a week to the Sepulture, and a week to the Resurrection: from the 14th to the 20th moon for the Passion, from the 15th to the 21st for the Sepulture
p.69and from the 16th to the 22nd for the Resurrection, consecrating a week for reverence of the Lord's Day.
Cologne Prologue (Krusch, Studien 1: 232-233=PL Supplement 3: 433-434)For, if the fourteenth moon were assigned to the Resurrection, as you do, then the thirteenth would fall on the Sepulture and the twelfth on the Passion, in an inverted order.