Forty days after Jesus’ Glorious Resurrection, Our Lord ascended into Heaven (Acts 1:6-11). The Catechism of the Catholic Church (paragraph 665) says, “Christ’s Ascension marks the definitive entrance of Jesus’ humanity into God’s heavenly domain, whence he will come again (cf. Acts 1:11); this humanity in the meantime hides him from the eyes of men (cf. Col 3:3).”
In 2024, the Feast of the Ascension is on Thursday, May 9, but in many dioceses it is transferred to Sunday, May 12. (Source: EWTN)