Shaykh Ibn Baaz رحمه الله said, “Certainly, celebrating the fifteenth night of Shaban by performing supererogatory prayers or other acts of worship, and singling out its day with fast is a despicable innovation, as viewed by the majority of the people of knowledge. There is no basis for it in the pure Shari'ah, rather, it is from that which arose in Islaam after the era of the Companions رضي الله عنه.” [حكم الا حتفال بليله النصف من شعبان]