Formally known as the Solemnity of the Most Sacred Heart of Jesus (Latin: Sollemnitas Sacratissimi Cordis Iesu), this is a moveable feast that honors the Sacred Heart.
In 1675, Jesus told St. Margaret Mary Alacoque that He wanted the Feast of the Sacred Heart to be celebrated on the Friday after the Corpus Christi octave.
In 1856, the Feast of the Sacred Heart became a universal feast.