What is the significance of praying during the night of 15 Shaban and fasting during its day?
There are two views on the subject. Some Muslims consider it very important, quoting verses 44:3-4 and some ahadith. Others believe verses 44:3-4 are talking about the night of Qadr mentioned in surah 97. They also believe that the ahadith about 15 Shaban are either weak or some of them are referring to Lailatul Qadr, but they have errors in their text that have led to the confusion. I agree with the second view.