Well, the Hijri date 20 Dhul Qidah 1399 corresponds to the Gregorian date Thursday, 11 October 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 Thursday without any doubt. The Arabic date 1399/11/20 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 11 October 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Dhul Qidah 1399 AH to its equivalent Gregorian date.
فَبِأَىِّ ءَالَآءِ رَبِّكُمَا تُكَذِّبَانِ
Which is it, of the favours of your Lord, that ye deny?
Surah Ar-Rahmaan(55:42)
Sahih al-Bukhari
Fasting
Chapter: Taking a bath by a person observing Saum (fast)
Narrated Abu Bakr bin `Abdur-Rahman:
My father and I went to `Aisha and she said, "I testify that Allah's Messenger (ﷺ) at times used to get up in the morning in a state of Janaba from sexual intercourse, not from a wet dream and then he would fast that day." Then he went to Um Salama and she also narrated a similar thing.
Sahih al-Bukhari 1931, 1932