Well, the Hijri date 21 Muharram 1191 corresponds to the Gregorian date Friday, 28 February 1777. This date lies in the first month of the Hijri year 1191 AH, which is Muharram of 1191 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1191/01/21 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 28 February 1777 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Muharram 1191 AH to its equivalent Gregorian date.
وَمَا يَسْتَوِى ٱلْبَحْرَانِ هَٰذَا عَذْبٌۭ فُرَاتٌۭ سَآئِغٌۭ شَرَابُهُۥ وَهَٰذَا مِلْحٌ أُجَاجٌۭ ۖ وَمِن كُلٍّۢ تَأْكُلُونَ لَحْمًۭا طَرِيًّۭا وَتَسْتَخْرِجُونَ حِلْيَةًۭ تَلْبَسُونَهَا ۖ وَتَرَى ٱلْفُلْكَ فِيهِ مَوَاخِرَ لِتَبْتَغُوا۟ مِن فَضْلِهِۦ وَلَعَلَّكُمْ تَشْكُرُونَ
And the two seas are not alike: this, fresh, sweet, good to drink, this (other) bitter, salt. And from them both ye eat fresh meat and derive the ornament that ye wear. And thou seest the ship cleaving them with its prow that ye may seek of His bounty, and that haply ye may give thanks.
Surah Faatir(35:12)