Well, the Hijri date 14 Rabi Al Thani 1399 corresponds to the Gregorian date Monday, 12 March 1979. This date lies in the fourth month of the Hijri year 1399 AH, which is Rabi Al-Thani of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1399/04/14 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 12 March 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 14 Rabi Al Thani 1399 AH to its equivalent Gregorian date.
۞ وَٱعْلَمُوٓا۟ أَنَّمَا غَنِمْتُم مِّن شَىْءٍۢ فَأَنَّ لِلَّهِ خُمُسَهُۥ وَلِلرَّسُولِ وَلِذِى ٱلْقُرْبَىٰ وَٱلْيَتَٰمَىٰ وَٱلْمَسَٰكِينِ وَٱبْنِ ٱلسَّبِيلِ إِن كُنتُمْ ءَامَنتُم بِٱللَّهِ وَمَآ أَنزَلْنَا عَلَىٰ عَبْدِنَا يَوْمَ ٱلْفُرْقَانِ يَوْمَ ٱلْتَقَى ٱلْجَمْعَانِ ۗ وَٱللَّهُ عَلَىٰ كُلِّ شَىْءٍۢ قَدِيرٌ
And know that whatever ye take as spoils of war, lo! a fifth thereof is for Allah, and for the messenger and for the kinsman (who hath need) and orphans and the needy and the wayfarer, if ye believe in Allah and that which We revealed unto Our slave on the Day of Discrimination, the day when the two armies met. And Allah is Able to do all things.
Surah Al-Anfaal(8:41)