A quote of a reference book states Jesus did not specifically state how often the Memorial of his death was to be kept However he instituted it on the date of the Jewish Passover which was replaced among his disciples by the Memorial of Christ s death The Passover was an annual event celebrated on Nisan 14 Similarly the Jewish Festival of Unfermented Cakes the Festival of Weeks Pentecost the Festival of Booths or Ingathering and the Day of Atonement were all held once a year