Divine Mercy Sunday (also known as the Feast of the Divine Mercy) is a feast day that is observed in the Roman Rite calendar, as well as in some Anglo-Catholics of the Church of England. It is celebrated on the Second Sunday of Easter, which concludes the Octave of Easter. It is originally based on the Catholic devotion to the Divine Mercy that Faustina Kowalska reported as part of her encounter with Jesus. It is associated with special promises from Jesus and indulgences issued by the Catholic Church.
The feast of Divine Mercy, according to the diary of Kowalska, receives from Jesus the biggest promises of grace related to the Devotion of Divine Mercy, in particular, that a person who goes to sacramental confession (the confession may take place some days before) and receives holy communion on that day, shall obtain the total expiation of all sins and punishment. That means each person would go immediately after death to heaven without suffering in purgatory. Additionally, the Roman Catholic Church grants a plenary indulgence by reciting some simple prayers.