The Catechism in Questions & Answers

56. What does it mean to say: “God is the Eternal”?

God is without beginning and without end. There are no chronological limitations for Him. God is the Creator of time and is Lord over it.

“Before the mountains were brought forth, or ever You had formed the earth and the world, even from everlasting to everlasting, You are God.” Psalm 90: 2