Well, the Hijri date 5 Shawwal 1399 corresponds to the Gregorian date Monday, 27 August 1979. This date lies in the tenth month of the Hijri year 1399 AH, which is Shawwal of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1399/10/05 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 27 August 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 5 Shawwal 1399 AH to its equivalent Gregorian date.
خَٰلِدِينَ فِيهَا مَا دَامَتِ ٱلسَّمَٰوَٰتُ وَٱلْأَرْضُ إِلَّا مَا شَآءَ رَبُّكَ ۚ إِنَّ رَبَّكَ فَعَّالٌۭ لِّمَا يُرِيدُ
Abiding there so long as the heavens and the earth endure save for that which thy Lord willeth. Lo! thy Lord is Doer of what He will.
Surah Hud(11:107)