Divine Mercy
By Eugeniusz Kazimirowski
Divine Mercy Sunday is the culmination of Mercy, of which God says "I desire that the Feast of Mercy ...be solemnly celebrated on the first Sunday after Easter... The soul that will go to Confession and receive Holy Communion (in a state of grace on this day) shall obtain complete forgiveness of sins and punishment." (entry 699)
Divine Mercy Sunday is always the Sunday after Easter.
Above is a countdown until the next Divine Mercy Sunday; that is if you go to Confession and receive Holy Communion (in a state of grace on this day), you will receive complete forgiveness of sins and punishment.