Fasting 27th of Rajab: Any Merits?

It should be noted, first of all, that the exact date of Al-Israa’ and Al-Mi`raj is not known. There is no evidence to support the saying that it happened on 27th of Rajab. Even if 27th of Rajab is the day of Al-Israa’ and Al-Mi`raj, there is no way to say that we have to fast that day, since we cannot innovate fasting on our own without having evidence from the sources of Shari`ah supporting it.

However, if a person customarily fasts on Mondays and Thursdays and 27th of Rajab falls on one of those two days, then there is nothing wrong in fasting on that day.