I cannot think of a time in which the Catholic Church had three major celebrations take place on the same day. May 1, 2011 marked the feast day of St.. Joseph the Worker, Divine Mercy Sunday and the beatification of Pope John Paul II.
The feast day of St. Joseph the Worker was instituted by Pope Pius XII apparently in response to the Communist May Day. The feast was intended to focus attention on the dignity of all work and workers. Now workers around the world turn to St. Joseph for intercession for help with their work and when searching for work. This is fitting since Joseph drop everything to flee to Egypt where he would have to find new work to support the Holy Family.
Pope John Paul II instituted the feast of Divine Mercy Sunday on April 30, 2000. The Pope made the surprise announcement during his homily at the canonization mass for St. Faustina. Divine Mercy is celebrated the first Sunday following Easter. The feast was requested by our Lord in a vision to young Faustina. The Lord promised Faustina that "the soul that will go to Confession and receive Holy Communion shall obtain complete forgiveness of sins and punishment."
Pope John Paul II is now remembered Blessed John Paul II, while to others he is already John Paul the Great. WIth his beatification today, the universal church may publicly ask for his intercession. John Paul is responsible for leading in the Catechism of the Catholic Church, a collection of the Church's magesterium. Additionally, he was known as the most travelled pope, he canonized hundreds of saints and he is the mercy pope. As a Polish bishop he led the cause for the canonization of Faustina. Years later as Pope, he oversaw her canonization and the institution of Divine Mercy as a universal feast day. John Paul actually died after attending the Vigil mass of Divine Mercy.