Well, the Hijri date 29 Shawwal 1399 corresponds to the Gregorian date Thursday, 20 September 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 Thursday without any doubt. The Arabic date 1399/10/29 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 20 September 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 29 Shawwal 1399 AH to its equivalent Gregorian date.
وَإِذَا مَآ أُنزِلَتْ سُورَةٌۭ فَمِنْهُم مَّن يَقُولُ أَيُّكُمْ زَادَتْهُ هَٰذِهِۦٓ إِيمَٰنًۭا ۚ فَأَمَّا ٱلَّذِينَ ءَامَنُوا۟ فَزَادَتْهُمْ إِيمَٰنًۭا وَهُمْ يَسْتَبْشِرُونَ
And whenever a surah is revealed there are some of them who say: Which one of you hath thus increased in faith? As for those who believe, it hath increased them in faith and they rejoice (therefor).
Surah At-Tawba(9:124)
Sahih al-Bukhari
Wills and Testaments (Wasaayaa)
Chapter: Animals, property, gold and silver as endowments
Narrated Ibn `Umar:
Once `Umar gave a horse in charity to be used in holy fighting. It had been given to him by Allah's Apostle . `Umar gave it to another man to ride. Then `Umar was informed that the man put the horse for sale, so he asked Allah's Messenger (ﷺ) whether he could buy it. Allah's Messenger (ﷺ) replied, "You should not buy it, for you should not take back what you have given in charity."
Sahih al-Bukhari 2775
