The 8th day that Parshas Shemini refers to was the day the mishkan (temple) was erected, Rosh Chodesh Nissan. This took place exactly one year after Yetzias Mitzrayim, the time when the Jews left Egypt. The redemption took place in the Springtime as it was a time of blossoming and developing for the nation. We have a commandment to remember this redemption every day of our lives. Why is this so important? What do we accomplish by constantly remembering and speaking about it? When saying the story of the redemption from Egypt, we are testifying to the strength of Hashem and we realize that it is a privilege to be able to serve Him.