Daniel refers to the "Ancient of Days" three times.

............In Chapter 7:13, he distinguishes between the "Son of Man" and the "Ancient of Days," but in vs 9 & 22 he associates the Ancient of Days" with a "Throne of Judgment", as God the Father has given all judgment to the Son.

"For the Father judgeth no man, but hath committed all judgment unto the Son:"
...............................John 5:22