Is it considered a religious innovation for a group of people to arrange a monthly meeting to gather in the mosque in order to perform late night prayers, have dinner and have a religious lesson? Is it permissible to recite the Qunoot (i.e. supplication during prayers) in the five obligatory prayers or is it only permissible in one or two prayers or something of that sort?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

A religious innovation according to the scholars is defined as an act of worship that was not performed by the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, while there is a reason for it and there is no impediment to perform it.

Hence, gathering on a certain day each month in order to perform night prayers and attend a religious lesson is not considered a religious innovation as long as this group could not find other times to do this. Also, they must not forbid their participants from performing night prayers, attending other religious lessons or performing any other act of worship whenever they can. It is good if they devote this gathering for discussing the affairs of Muslims and Da‘wah issues together.

However, if they set this specific day each month for their meeting obliging their participants to attend and considering missing such a gathering or modifying its program as forbidden and rejected, then it is considered a religious innovation and is rejected (according to the Islamic Sharee‘ah). 

As for your question about the Qunoot, it is not obligatory to recite the supplication of Qunoot in all five obligatory prayers or in any of them. However, Imaam Maalik, Ash-Shaafi‘i and those who adopted their opinions (in this regard) believed that the Qunoot is recommended but not obligatory in the Fajr prayer.

As for the other obligatory prayers, Qunoot is allowable in the case of a disaster or if a calamity befalls the Muslims.