We do not have a solid date for the writing of Jude. As a result there is a wide difference in opinions concerning when this book was written. Most historians agree that it was written during Jude's ministry in Palestine in the A.D. 60's to A.D. 80's.

Sources:
Encountering the New Testament, Walter A. Elwell / Robert W. Yarbrough, 1998, Baker Books, page 371