Well, the Hijri date 17 Rabi Al Thani 1420 corresponds to the Gregorian date Friday, 30 July 1999. This date lies in the fourth month of the Hijri year 1420 AH, which is Rabi Al-Thani of 1420 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1420/04/17 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 30 July 1999 to its equivalent Arabic date.
The following is the conversion of the Arabic date 17 Rabi Al Thani 1420 AH to its equivalent Gregorian date.
وَيَجْعَلُونَ لِلَّهِ ٱلْبَنَٰتِ سُبْحَٰنَهُۥ ۙ وَلَهُم مَّا يَشْتَهُونَ
And they assign unto Allah daughters - Be He Glorified! - and unto themselves what they desire;
Surah An-Nahl(16:57)