MIRAJ
Among the prohibited types of fasting is any kind of fasting people initiate on their own without any Shari`ah text or evidence. An example of this is the fasting on the 27th of Rajab thinking that it is the day that followed the night of Al-Israa’ and Al-Mi`raj.
Some people would fast on that day as a token of gratitude and thankfulness to Allah for the blessing of Al-Israa’ and Al-Mi`raj. It is really important for a Muslim to prove thankful in the remembrance of every event that brought blessings to the Muslim Ummah. These events are many indeed.
However, this thankfulness does not mean that a Muslim has to fast. Almighty Allah reminds Muslims of so many blessings He has given to them. Allah says: (O ye who believe! Remember Allah's favor unto you when there came against you hosts, and We sent against them a great wind and hosts ye could not see.) (Al-Ahzab 33: 9) However, Almighty Allah did not ask them to fast and they never did.
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As far as Muslims are concerned, there is no particular celebration, fast or prayer to commemorate israa and mi’raj. Neither the Qur’an nor the sunnah of the Prophet says anything about celebrating it. But in some places, the Muslims themselves have started to have commemorative functions, where the story of mi’raj is told in poetry, chants or lectures. Sweets and food are distributed in a festive atmosphere.
To add a feast or a fast or some such act of religious significance to what the Prophet has taught us is called bid’ah (innovation in religious practice) in the terminology of Islam. Infact, bid’ah is strongly discouraged. Scholars, who maintain such gatherings, mean to remind the Muslims of the importance of mi’raj, in the history of Islam or of the city of Jerusalem and for the sake of children enjoying the occasion and drawing lessons from it as a social event. This is usually with a view of helping our brothers and sisters who are suffering in Palestine, which is definitely permissible.
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As far as the Muslims are concerned, there is no particular celebration, fast or prayer to commemorate Isra’ wal-Mi`raj. But in some places, the Muslims themselves have started to have commemorative functions, where the story of the night journey is told in poetry or lectures. While the Prophet himself (peace be upon him) did not establish these practices, there are scholars who maintain that gatherings meant to remind the Muslims of the importance of Mi`raj in the history of Islam, or to remind us of the importance of love for the Prophet (peace be upon him) and the significance of the city of Jerusalem, are permissible.
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It goes without saying that the obligatory fast is the one in Ramadan, but perpetual fasting all through Rajab and Sha`ban and joining them with Ramadan is not recommended by some scholars. However, offering fast for some days in Rajab and Sha`ban is recommended, and earns a great reward.