Well, the Hijri date 15 Shawwal 1511 corresponds to the Gregorian date Thursday, 6 May 2088. This date lies in the tenth month of the Hijri year 1511 AH, which is Shawwal of 1511 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1511/10/15 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 6 May 2088 to its equivalent Arabic date.
The following is the conversion of the Arabic date 15 Shawwal 1511 AH to its equivalent Gregorian date.
وَلَا تُؤْمِنُوٓا۟ إِلَّا لِمَن تَبِعَ دِينَكُمْ قُلْ إِنَّ ٱلْهُدَىٰ هُدَى ٱللَّهِ أَن يُؤْتَىٰٓ أَحَدٌۭ مِّثْلَ مَآ أُوتِيتُمْ أَوْ يُحَآجُّوكُمْ عِندَ رَبِّكُمْ ۗ قُلْ إِنَّ ٱلْفَضْلَ بِيَدِ ٱللَّهِ يُؤْتِيهِ مَن يَشَآءُ ۗ وَٱللَّهُ وَٰسِعٌ عَلِيمٌۭ
And believe not save in one who followeth your religion - Say (O Muhammad): Lo! the guidance is Allah's Guidance - that anyone is given the like of that which was given unto you or that they may argue with you in the presence of their Lord. Say (O Muhammad): Lo! the bounty is in Allah's hand. He bestoweth it on whom He will. Allah is All-Embracing, All-Knowing.
Surah Aal-i-Imraan(3:73)