Well, the Hijri date 20 Jumada Al Oula 1399 corresponds to the Gregorian date Tuesday, 17 April 1979. This date lies in the fifth month of the Hijri year 1399 AH, which is Jumada Al-Awwal of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Tuesday without any doubt. The Arabic date 1399/05/20 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 17 April 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Jumada Al Oula 1399 AH to its equivalent Gregorian date.
قُل لَّوْ كَانَ مَعَهُۥٓ ءَالِهَةٌۭ كَمَا يَقُولُونَ إِذًۭا لَّٱبْتَغَوْا۟ إِلَىٰ ذِى ٱلْعَرْشِ سَبِيلًۭا
Say (O Muhammad, to the disbelievers): If there were other gods along with Him, as they say, then had they sought a way against the Lord of the Throne.
Surah Al-Israa(17:42)
Sahih al-Bukhari
Knowledge
Chapter: The knowledge and its teaching and preaching at night
Narrated Um Salama:
One night Allah's Messenger (ﷺ) got up and said, "Subhan Allah! How many afflictions have been descended tonight and how many treasures have been disclosed! Go and wake the sleeping lady occupants of these dwellings (his wives) up (for prayers). A well-dressed (soul) in this world may be naked in the Hereafter. "
Sahih al-Bukhari 115