Well, the Hijri date 21 Shawwal 1399 corresponds to the Gregorian date Wednesday, 12 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 Wednesday without any doubt. The Arabic date 1399/10/21 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 September 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Shawwal 1399 AH to its equivalent Gregorian date.
فَخَسَفْنَا بِهِۦ وَبِدَارِهِ ٱلْأَرْضَ فَمَا كَانَ لَهُۥ مِن فِئَةٍۢ يَنصُرُونَهُۥ مِن دُونِ ٱللَّهِ وَمَا كَانَ مِنَ ٱلْمُنتَصِرِينَ
So We caused the earth to swallow him and his dwelling-place. Then he had no host to help him against Allah, nor was he of those who can save themselves.
Surah Al-Qasas(28:81)
Sahih al-Bukhari
To make the Heart Tender (Ar-Riqaq)
Chapter: Seventy thousand will enter Paradise without accounts.
Narrated Ibn `Abbas:
The Prophet (ﷺ) said, "The people were displayed in front of me and I saw one prophet passing by with a large group of his followers, and another prophet passing by with only a small group of people, and another prophet passing by with only ten (persons), and another prophet passing by with only five (persons), and another prophet passed by alone. And then I looked and saw a large multitude of people, so I asked Gabriel, "Are these people my followers?' He said, 'No, but look towards the horizon.' I looked and saw a very large multitude of people. Gabriel said. 'Those are your followers, and those are seventy thousand (persons) in front of them who will neither have any reckoning of their accounts nor will receive any punishment.' I asked, 'Why?' He said, 'For they used not to treat themselves with branding (cauterization) nor with Ruqya (get oneself treated by the recitation of some Verses of the Qur'an) and not to see evil omen in things, and they used to put their trust (only) in their Lord." On hearing that, 'Ukasha bin Mihsan got up and said (to the Prophet), "Invoke Allah to make me one of them." The Prophet (ﷺ) said, "O Allah, make him one of them." Then another man got up and said (to the Prophet), "Invoke Allah to make me one of them." The Prophet (ﷺ) said, 'Ukasha has preceded you."
Sahih al-Bukhari 6541