Well, the Hijri date 28 Shawwal 1411 corresponds to the Gregorian date Sunday, 12 May 1991. This date lies in the tenth month of the Hijri year 1411 AH, which is Shawwal of 1411 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1411/10/28 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 May 1991 to its equivalent Arabic date.
The following is the conversion of the Arabic date 28 Shawwal 1411 AH to its equivalent Gregorian date.
وَيَعْبُدُونَ مِن دُونِ ٱللَّهِ مَا لَا يَمْلِكُ لَهُمْ رِزْقًۭا مِّنَ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ شَيْـًۭٔا وَلَا يَسْتَطِيعُونَ
And they worship beside Allah that which owneth no provision whatsoever for them from the heavens or the earth, nor have they (whom they worship) any power.
Surah An-Nahl(16:73)