Well, the Hijri date 13 Shaban 1187 corresponds to the Gregorian date Friday, 29 October 1773. This date lies in the eighth month of the Hijri year 1187 AH, which is Shaban of 1187 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1187/08/13 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 1773 to its equivalent Arabic date.
The following is the conversion of the Arabic date 13 Shaban 1187 AH to its equivalent Gregorian date.
لَيْسَ لَكَ مِنَ ٱلْأَمْرِ شَىْءٌ أَوْ يَتُوبَ عَلَيْهِمْ أَوْ يُعَذِّبَهُمْ فَإِنَّهُمْ ظَٰلِمُونَ
It is no concern at all of thee (Muhammad) whether He relent toward them or punish them; for they are evil-doers.
Surah Aal-i-Imraan(3:128)