Well, the Hijri date 7 Rabi Al Awwal 1187 corresponds to the Gregorian date Friday, 28 May 1773. This date lies in the third month of the Hijri year 1187 AH, which is Rabi Al-Awwal of 1187 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1187/03/07 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 28 May 1773 to its equivalent Arabic date.
The following is the conversion of the Arabic date 7 Rabi Al Awwal 1187 AH to its equivalent Gregorian date.
ذَٰلِكَ أَدْنَىٰٓ أَن يَأْتُوا۟ بِٱلشَّهَٰدَةِ عَلَىٰ وَجْهِهَآ أَوْ يَخَافُوٓا۟ أَن تُرَدَّ أَيْمَٰنٌۢ بَعْدَ أَيْمَٰنِهِمْ ۗ وَٱتَّقُوا۟ ٱللَّهَ وَٱسْمَعُوا۟ ۗ وَٱللَّهُ لَا يَهْدِى ٱلْقَوْمَ ٱلْفَٰسِقِينَ
Thus it is more likely that they will bear true witness or fear that after their oaths the oaths (of others) will be taken. So be mindful of your duty (to Allah) and hearken. Allah guideth not the froward folk.
Surah Al-Maaida(5:108)