One reason some of those who affiliate themselves with the Sunnis go to excess in venerating that day may be simply to counter the Rāfiḍah. Yet Satan’s aim is to deflect people from the Straight Path, and he is indifferent to which side of the divide they end up on.
Therefore, every one of these newly-introduced practices should be avoided.
In the same vein falls the month of Rajab. It is indeed one of the sacred months, and it is related from the Prophet—may Allah bless him and grant him peace—that when Rajab began he would say, “O Allah, bless us in Rajab and Shaʿbān, and let us reach Ramadan.”
Beyond this, no other authentic ḥadīth concerning the virtues of Rajab is established from the Prophet, peace and blessings be upon him. In fact, most of the reports attributed to him about Rajab are fabricated. If the falsehood of a report is not known for certain, narrating it in the context of meritorious deeds is a minor matter; but once its spurious nature is clear, it is forbidden to transmit it unless its status is explained.
For the Prophet—may Allah bless him and grant him peace—said, “Whoever relates a ḥadīth from me while thinking it to be false is one of the two liars.”