Passover is an important event
n"The annual festivals commanded by God all prefigured some event relating to the Messiah. Also, something worthy of mention is that each of the festivals which have been fulfilled met their fulfillment on the actual day of celebration. That is to say, Christ was sacrificed as our paschal lamb on the day of Passover. Christ presented Himself before the Father on the day of Firstfruits. These parallels hold true to each of the holidays. Type met anti-type on the very same day, and it was all fulfilled in that day." 

- Atoning for the Day of Atonement,
      by Raymond  Thompson,  20 April 2008       (http://www.spectrummagazine.org/collegiate/2008/04/20/atoning_day_atonement)