Well, the Hijri date 12 Muharram 1237 corresponds to the Gregorian date Monday, 8 October 1821. This date lies in the first month of the Hijri year 1237 AH, which is Muharram of 1237 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1237/01/12 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 8 October 1821 to its equivalent Arabic date.
The following is the conversion of the Arabic date 12 Muharram 1237 AH to its equivalent Gregorian date.
لَوْ أَنزَلْنَا هَٰذَا ٱلْقُرْءَانَ عَلَىٰ جَبَلٍۢ لَّرَأَيْتَهُۥ خَٰشِعًۭا مُّتَصَدِّعًۭا مِّنْ خَشْيَةِ ٱللَّهِ ۚ وَتِلْكَ ٱلْأَمْثَٰلُ نَضْرِبُهَا لِلنَّاسِ لَعَلَّهُمْ يَتَفَكَّرُونَ
If We had caused this Qur'an to descend upon a mountain, thou (O Muhammad) verily hadst seen it humbled, rent asunder by the fear of Allah. Such similitudes coin We for mankind that haply they may reflect.
Surah Al-Hashr(59:21)