Well, the Hijri date 21 Rajab 1506 corresponds to the Gregorian date Thursday, 8 April 2083. This date lies in the seventh month of the Hijri year 1506 AH, which is Rajab of 1506 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1506/07/21 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 8 April 2083 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Rajab 1506 AH to its equivalent Gregorian date.
يَٰقَوْمَنَآ أَجِيبُوا۟ دَاعِىَ ٱللَّهِ وَءَامِنُوا۟ بِهِۦ يَغْفِرْ لَكُم مِّن ذُنُوبِكُمْ وَيُجِرْكُم مِّنْ عَذَابٍ أَلِيمٍۢ
O our people! respond to Allah's summoner and believe in Him. He will forgive you some of your sins and guard you from a painful doom.
Surah Al-Ahqaf(46:31)