Well, the Hijri date 14 Shaban 1188 corresponds to the Gregorian date Wednesday, 19 October 1774. This date lies in the eighth month of the Hijri year 1188 AH, which is Shaban of 1188 AH. Both this Hijri and Gregorian date occur on the single day that is Wednesday without any doubt. The Arabic date 1188/08/14 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 19 October 1774 to its equivalent Arabic date.
The following is the conversion of the Arabic date 14 Shaban 1188 AH to its equivalent Gregorian date.
أَفَلَا يَتَدَبَّرُونَ ٱلْقُرْءَانَ ۚ وَلَوْ كَانَ مِنْ عِندِ غَيْرِ ٱللَّهِ لَوَجَدُوا۟ فِيهِ ٱخْتِلَٰفًۭا كَثِيرًۭا
Will they not then ponder on the Qur'an? If it had been from other than Allah they would have found therein much incongruity.
Surah An-Nisaa(4:82)