The Solemnity of the Assumption of the Blessed Virgin Mary is August 15th.
What does the Solemnity of the Assumption of the Blessed Virgin Mary celebrate?
On August 15th, the Church celebrates the fact that Mary, the Mother of God, was assumed into Heaven at the end of her earthly life.
The Catechism of the Catholic Church (CCC 974) teaches, “The Most Blessed Virgin Mary, when the course of her earthly life was completed, was taken up body and soul into the glory of heaven, where she already shares in the glory of her Son's Resurrection, anticipating the resurrection of all members of his Body.”

"Let .”
– Saint Pope John Paul II
What happened in the Assumption of Mary?
New Paragraph
Fven, for we were with him on the holn.”
2 Peter 1:16-18
Reflection
One of the Transfiguration accounts is read on the second Sunday of Lent each year, proclaiming Christ’s divinity to the Elect and baptized alike. The Gospel for the first Sunday of Lent, by contrast, is the story of the temptation in the desert—affirmation of Jesus’ humanity. The two distinct but inseparable natures of the Lord were a subject of much theological argument at the beginning of the Church’s history; it remains hard for believers to grasp.
-Franciscan Media