Well, the Hijri date 13 Rajab 1399 corresponds to the Gregorian date Friday, 8 June 1979. This date lies in the seventh month of the Hijri year 1399 AH, which is Rajab of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1399/07/13 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 8 June 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 13 Rajab 1399 AH to its equivalent Gregorian date.
سَخَّرَهَا عَلَيْهِمْ سَبْعَ لَيَالٍۢ وَثَمَٰنِيَةَ أَيَّامٍ حُسُومًۭا فَتَرَى ٱلْقَوْمَ فِيهَا صَرْعَىٰ كَأَنَّهُمْ أَعْجَازُ نَخْلٍ خَاوِيَةٍۢ
Which He imposed on them for seven long nights and eight long days so that thou mightest have seen men lying overthrown, as they were hollow trunks of palm-trees.
Surah Al-Haaqqa(69:7)
Sahih al-Bukhari
Bathing (Ghusl)
Chapter: A Junub person should perform ablution before sleeping
Narrated `Aisha:
Whenever the Prophet (ﷺ) intended to sleep while he was Junub, he used to wash his private parts and perform ablution like that for the prayer.
Sahih al-Bukhari 288