Well, the Hijri date 21 Rabi Al Awwal 1223 corresponds to the Gregorian date Monday, 16 May 1808. This date lies in the third month of the Hijri year 1223 AH, which is Rabi Al-Awwal of 1223 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1223/03/21 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 16 May 1808 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Rabi Al Awwal 1223 AH to its equivalent Gregorian date.
وَجَآءَ ٱلْمُعَذِّرُونَ مِنَ ٱلْأَعْرَابِ لِيُؤْذَنَ لَهُمْ وَقَعَدَ ٱلَّذِينَ كَذَبُوا۟ ٱللَّهَ وَرَسُولَهُۥ ۚ سَيُصِيبُ ٱلَّذِينَ كَفَرُوا۟ مِنْهُمْ عَذَابٌ أَلِيمٌۭ
And those among the wandering Arabs who had an excuse came in order that permission might be granted them. And those who lied to Allah and His messenger sat at home. A painful doom will fall on those of them who disbelieve.
Surah At-Tawba(9:90)