Well, the Hijri date 27 Shaban 1406 corresponds to the Gregorian date Tuesday, 6 May 1986. This date lies in the eighth month of the Hijri year 1406 AH, which is Shaban of 1406 AH. Both this Hijri and Gregorian date occur on the single day that is Tuesday without any doubt. The Arabic date 1406/08/27 is calculated using the Umm Al-Qura calendar and the sighting of the moon. One thing to remember is that this Arabic date may occur on different Gregorian date depending upon the region and country and obviously the moon.
If you are still not sure about the date then you can use our Arabic date converter.
The following is the conversion of the Gregorian date 6 May 1986 to its equivalent Arabic date.
The following is the conversion of the Arabic date 27 Shaban 1406 AH to its equivalent Gregorian date.
فَغَشَّىٰهَا مَا غَشَّىٰ
So that there covered them that which did cover.
Surah An-Najm(53:54)
Sahih al-Bukhari
Virtues of the Qur'an
Chapter: The superiority of Surat Al-Kahf (No.18)
Narrated Al-Bara':
A man was reciting Surat Al-Kahf and his horse was tied with two ropes beside him. A cloud came down and spread over that man, and it kept on coming closer and closer to him till his horse started jumping (as if afraid of something). When it was morning, the man came to the Prophet, and told him of that experience. The Prophet (ﷺ) said, "That was As-Sakina (tranquility) which descended because of (the recitation of) the Qur'an."
Sahih al-Bukhari 5011