BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
The Ewoks' Hang-Gliding Adventure is a children's book written by Judy Herbstman with illustrations by Pat Paris. It was published in 1984.