The Catechism in Questions & Answers

195. How else is the return of Jesus Christ described?

The event of the return of Jesus Christ is also described as the “day of the Lord”, the “day of Christ”, the “future of our Lord”, the “revelation of Christ’s glory”, the “appearing” or “return of the Lord”, and the “return of Christ”.
This event is not the Last Judgement, but rather the moment when the bride of Christ will be caught up to heaven for the marriage of the Lamb.

“Let us be glad and rejoice and give Him glory, for the marriage of the Lamb has come, and His wife has made herself ready.”
Revelation 19: 7