Well, the Hijri date 22 Muharram 1236 corresponds to the Gregorian date Sunday, 29 October 1820. This date lies in the first month of the Hijri year 1236 AH, which is Muharram of 1236 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1236/01/22 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 29 October 1820 to its equivalent Arabic date.
The following is the conversion of the Arabic date 22 Muharram 1236 AH to its equivalent Gregorian date.
فَلَا تَكُ فِى مِرْيَةٍۢ مِّمَّا يَعْبُدُ هَٰٓؤُلَآءِ ۚ مَا يَعْبُدُونَ إِلَّا كَمَا يَعْبُدُ ءَابَآؤُهُم مِّن قَبْلُ ۚ وَإِنَّا لَمُوَفُّوهُمْ نَصِيبَهُمْ غَيْرَ مَنقُوصٍۢ
So be not thou in doubt concerning that which these (folk) worship. They worship only as their fathers worshipped aforetime. Lo! we shall pay them their whole due unabated.
Surah Hud(11:109)