Well, the Hijri date 9 Dhul Qidah 1399 corresponds to the Gregorian date Sunday, 30 September 1979. This date lies in the eleventh month of the Hijri year 1399 AH, which is Dhu Al-Qidah of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1399/11/09 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 September 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 9 Dhul Qidah 1399 AH to its equivalent Gregorian date.
وَأَنِ ٱحْكُم بَيْنَهُم بِمَآ أَنزَلَ ٱللَّهُ وَلَا تَتَّبِعْ أَهْوَآءَهُمْ وَٱحْذَرْهُمْ أَن يَفْتِنُوكَ عَنۢ بَعْضِ مَآ أَنزَلَ ٱللَّهُ إِلَيْكَ ۖ فَإِن تَوَلَّوْا۟ فَٱعْلَمْ أَنَّمَا يُرِيدُ ٱللَّهُ أَن يُصِيبَهُم بِبَعْضِ ذُنُوبِهِمْ ۗ وَإِنَّ كَثِيرًۭا مِّنَ ٱلنَّاسِ لَفَٰسِقُونَ
So judge between them by that which Allah hath revealed, and follow not their desires, but beware of them lest they seduce thee from some part of that which Allah hath revealed unto thee. And if they turn away, then know that Allah's Will is to smite them for some sin of theirs. Lo! many of mankind are evil-livers.
Surah Al-Maaida(5:49)
Sahih al-Bukhari
Oaths and Vows
Chapter: If someone does something against his oath due to forgetfulness
Narrated `Abdullah bin `Amr bin Al-As:
While the Prophet (ﷺ) was delivering a sermon on the Day of Nahr (i.e., 10th Dhul-Hijja-Day of slaughtering the sacrifice), a man got up saying, "I thought, O Allah's Messenger (ﷺ), such-and-such a thing was to be done before such-and-such a thing." Another man got up, saying, "O Allah's Messenger (ﷺ)! As regards these three (acts of Hajj), thought so-and-so." The Prophet (ﷺ) said, "Do, and there is no harm," concerning all those matters on that day. And so, on that day, whatever question he was asked, he said, "Do it, do it, and there is no harm therein."
Sahih al-Bukhari 6665