Fasting in the month of Rajab & Shabaan.

Answer:
Fasting  in Rajab and Shabaan

In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright. We bear witness that there is none worthy of worship but Allah Alone, and we bear witness that Muhammad (saws) is His slave-servant and the seal of His Messengers.

Hadrat Aisha (r.a.) reported that she did not witness the Messenger of Allah (saws) fasting more in any month other than Ramadan than in the month of Shaabaan.  It was the Sunnah of the Messenger of Allah (saws) that he (saws) would fast many days in the month of Shabaan in preparation for the fasting of Ramadan, but he (saws) would stop fasting in the last few days of Shabaan so as not to mix them with the fasts of Ramadan.

Aishah said: "I never saw the Messenger of Allah (saws) fast a complete month save for Ramadan, and I have never seen him fast more in a month than he did in Sha'ban."

Related by al-Bukhari and Muslim.

Usamah ibn Zaid inquired: "O Messenger of Allah (saws), I never find you fasting in any month like you do during the month of Sha'ban."  The Prophet (saws) responded: "That is a month the people neglect. It comes between Rajab and Ramadan. It is a month in which the deeds are raised to the Lord of the Worlds. I love that my deeds be raised while I am fasting."
Related by Abu Dawud, an-Nasa'i, and by Ibn Khuzaimah.

Other than the month of Shabaan, there is no other month of the calendar which the Prophet (saws) specified as special or meritorious for voluntary fasting; but as was his normal practice he (saws) would, more often than not, perform voluntary fasts on the 13th, 14th and 15th of each of the other months, and the Mondays and Thursdays of the week.

There is absolutely no evidence in the authentic and established Sunnah that voluntary fasts during the month of Rajab has any more virtue or merit than the voluntary fasts of other months.

Whatever written of Truth and benefit is only due to Allah’s Assistance and Guidance, and whatever of error is of me alone.  Allah Alone Knows Best and He is the Only Source of Strength.