Well, the Hijri date 21 Rabi Al Thani 1411 corresponds to the Gregorian date Thursday, 8 November 1990. This date lies in the fourth month of the Hijri year 1411 AH, which is Rabi Al-Thani of 1411 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1411/04/21 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 November 1990 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Rabi Al Thani 1411 AH to its equivalent Gregorian date.
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ ٱسْتَجِيبُوا۟ لِلَّهِ وَلِلرَّسُولِ إِذَا دَعَاكُمْ لِمَا يُحْيِيكُمْ ۖ وَٱعْلَمُوٓا۟ أَنَّ ٱللَّهَ يَحُولُ بَيْنَ ٱلْمَرْءِ وَقَلْبِهِۦ وَأَنَّهُۥٓ إِلَيْهِ تُحْشَرُونَ
O ye who believe! Obey Allah, and the messenger when He calleth you to that which quickeneth you, and know that Allah cometh in between the man and his own heart, and that He it is unto Whom ye will be gathered.
Surah Al-Anfaal(8:24)