Should Laylat al-Nisf min Sha’ban Be Singled Out for Worship?
Question

I read in a book that fasting in the middle of Sha’ban is a kind of bid`ah, but in another book I read that one of the days on which it is mustahabb to fast is the middle of Sha’ban.  What is the definitive ruling on this?
Praise be to Allah.Laylat al-Nisf min Sha’ban (15th Shaban): Any Virtues?
Shaykh Ibn Jibrin said:
There is no sahih marfu’ report that speaks of the virtue of the middle of Sha’ban that may be followed, not even  in the chapters on al-Fadail (chapters on virtues in books of hadith etc.). Some maqtu’ reports (reports whose isnads do not go back further than the Tabi’in) have been narrated from some of the Tabi’in, and there are some hadiths, the best of which are mawdu’ (fabricated) or da’if jiddan (very weak). 
These reports became very well known in some countries which were overwhelmed by ignorance; these reports suggest that people’s lifespans are written on that day or that it is decided on that day who is to die in the coming year. 
On this basis, it is not prescribed to spend this night in prayer or to fast on this day, or to single it out for certain acts of worship. One should not be deceived by the large numbers of ignorant people who do these things. 
Offering qiyam on Laylat al-Nisf min Sha’ban
If a person wants to pray qiyam on laylat al-nisf min Sha’ban  as he does on other nights – without doing anything extra or singling this night out for anything – then that is OK. 
The same applies if he fasts the day of the fifteenth of Sha’ban because it happens to be one of the ayyam al-bid, along with the fourteenth and thirteenth of the month, or because it happens to be a Monday or Thursday. 
If the fifteenth (of Sha’ban) coincides with a Monday or Thursday, there is nothing wrong with that (fasting on that day), so long as he is not seeking extra reward that has not been proven (in the sahih texts). 
And Allah knows best.