Well, the Hijri date 18 Shaban 1399 corresponds to the Gregorian date Thursday, 12 July 1979. This date lies in the eighth month of the Hijri year 1399 AH, which is Shaban of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1399/08/18 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 July 1979 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Shaban 1399 AH to its equivalent Gregorian date.
لَّا يَمْلِكُونَ ٱلشَّفَٰعَةَ إِلَّا مَنِ ٱتَّخَذَ عِندَ ٱلرَّحْمَٰنِ عَهْدًۭا
They will have no power of intercession, save him who hath made a covenant with his Lord.
Surah Maryam(19:87)
Sahih al-Bukhari
Divorce
Chapter: "O Prophet! Why do you forbid that which Allah has allowed to you...?
Narrated `Ubaid bin `Umar:
I heard `Aisha saying, "The Prophet (ﷺ) used to stay for a long while with Zanab bint Jahsh and drink honey at her house. So Hafsa and I decided that if the Prophet (ﷺ) came to anyone of us, she should say him, "I detect the smell of Maghafir (a nasty smelling gum) in you. Have you eaten Maghafir?' " So the Prophet (ﷺ) visited one of them and she said to him similarly. The Prophet (ﷺ) said, "Never mind, I have taken some honey at the house of Zainab bint Jahsh, but I shall never drink of it anymore." So there was revealed: 'O Prophet ! Why do you ban (for you) that which Allah has made lawful for you . . . If you two (wives of Prophet) turn in repentance to Allah,' (66.1-4) addressing Aisha and Hafsa. 'When the Prophet (ﷺ) disclosed a matter in confidence to some of his wives.' (66.3) namely his saying: But I have taken some honey."
Sahih al-Bukhari 5267