Well, the Hijri date 29 Shaban 1237 corresponds to the Gregorian date Monday, 20 May 1822. This date lies in the eighth month of the Hijri year 1237 AH, which is Shaban of 1237 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1237/08/29 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 20 May 1822 to its equivalent Arabic date.
The following is the conversion of the Arabic date 29 Shaban 1237 AH to its equivalent Gregorian date.
مَّا كَانَ ٱللَّهُ لِيَذَرَ ٱلْمُؤْمِنِينَ عَلَىٰ مَآ أَنتُمْ عَلَيْهِ حَتَّىٰ يَمِيزَ ٱلْخَبِيثَ مِنَ ٱلطَّيِّبِ ۗ وَمَا كَانَ ٱللَّهُ لِيُطْلِعَكُمْ عَلَى ٱلْغَيْبِ وَلَٰكِنَّ ٱللَّهَ يَجْتَبِى مِن رُّسُلِهِۦ مَن يَشَآءُ ۖ فَـَٔامِنُوا۟ بِٱللَّهِ وَرُسُلِهِۦ ۚ وَإِن تُؤْمِنُوا۟ وَتَتَّقُوا۟ فَلَكُمْ أَجْرٌ عَظِيمٌۭ
It is not (the purpose) of Allah to leave you in your present state till He shall separate the wicked from the good. And it is not (the purpose of) Allah to let you know the Unseen. But Allah chooseth of His messengers whom He will, (to receive knowledge thereof). So believe in Allah and His messengers. If ye believe and ward off (evil), yours will be a vast reward.
Surah Aal-i-Imraan(3:179)