Well, the Hijri date 21 Rabi Al Awwal 1387 corresponds to the Gregorian date Thursday, 29 June 1967. This date lies in the third month of the Hijri year 1387 AH, which is Rabi Al-Awwal of 1387 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1387/03/21 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 29 June 1967 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Rabi Al Awwal 1387 AH to its equivalent Gregorian date.
وَإِذْ قُلْنَا لِلْمَلَٰٓئِكَةِ ٱسْجُدُوا۟ لِءَادَمَ فَسَجَدُوٓا۟ إِلَّآ إِبْلِيسَ كَانَ مِنَ ٱلْجِنِّ فَفَسَقَ عَنْ أَمْرِ رَبِّهِۦٓ ۗ أَفَتَتَّخِذُونَهُۥ وَذُرِّيَّتَهُۥٓ أَوْلِيَآءَ مِن دُونِى وَهُمْ لَكُمْ عَدُوٌّۢ ۚ بِئْسَ لِلظَّٰلِمِينَ بَدَلًۭا
And (remember) when We said unto the angels: Fall prostrate before Adam, and they fell prostrate, all save Iblis. He was of the jinn, so he rebelled against his Lord's command. Will ye choose him and his seed for your protecting friends instead of Me, when they are an enemy unto you? Calamitous is the exchange for evil-doers.
Surah Al-Kahf(18:50)
Sahih al-Bukhari
Virtues of Prayer at Masjid Makkah and Madinah
Chapter: The superiority of offering As-Salat in the Mosque of Makkah and Al-Madina
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "One prayer in my Mosque is better than one thousand prayers in any other mosque excepting Al-Masjid-AI-Haram."
Sahih al-Bukhari 1190