Well, the Hijri date 18 Rabi Al Thani 1399 corresponds to the Gregorian date Friday, 16 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 Friday without any doubt. The Arabic date 1399/04/18 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 March 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Rabi Al Thani 1399 AH to its equivalent Gregorian date.
أَلَمْ تَرَ أَنَّ ٱللَّهَ يُزْجِى سَحَابًۭا ثُمَّ يُؤَلِّفُ بَيْنَهُۥ ثُمَّ يَجْعَلُهُۥ رُكَامًۭا فَتَرَى ٱلْوَدْقَ يَخْرُجُ مِنْ خِلَٰلِهِۦ وَيُنَزِّلُ مِنَ ٱلسَّمَآءِ مِن جِبَالٍۢ فِيهَا مِنۢ بَرَدٍۢ فَيُصِيبُ بِهِۦ مَن يَشَآءُ وَيَصْرِفُهُۥ عَن مَّن يَشَآءُ ۖ يَكَادُ سَنَا بَرْقِهِۦ يَذْهَبُ بِٱلْأَبْصَٰرِ
Hast thou not seen how Allah wafteth the clouds, then gathereth them, then maketh them layers, and thou seest the rain come forth from between them; He sendeth down from the heaven mountains wherein is hail, and smiteth therewith whom He will, and averteth it from whom He will. The flashing of His lightning all but snatcheth away the sight.
Surah An-Noor(24:43)