Well, the Hijri date 28 Rajab 1236 corresponds to the Gregorian date Monday, 30 April 1821. This date lies in the seventh month of the Hijri year 1236 AH, which is Rajab of 1236 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1236/07/28 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 30 April 1821 to its equivalent Arabic date.
The following is the conversion of the Arabic date 28 Rajab 1236 AH to its equivalent Gregorian date.
وَإِنَّ مِنْهُمْ لَفَرِيقًۭا يَلْوُۥنَ أَلْسِنَتَهُم بِٱلْكِتَٰبِ لِتَحْسَبُوهُ مِنَ ٱلْكِتَٰبِ وَمَا هُوَ مِنَ ٱلْكِتَٰبِ وَيَقُولُونَ هُوَ مِنْ عِندِ ٱللَّهِ وَمَا هُوَ مِنْ عِندِ ٱللَّهِ وَيَقُولُونَ عَلَى ٱللَّهِ ٱلْكَذِبَ وَهُمْ يَعْلَمُونَ
And lo! there is a party of them who distort the Scripture with their tongues, that ye may think that what they say is from the Scripture, when it is not from the Scripture. And they say: It is from Allah, when it is not from Allah; and they speak a lie concerning Allah knowingly.
Surah Aal-i-Imraan(3:78)