Well, the Hijri date 18 Rabi Al Thani 1138 corresponds to the Gregorian date Sunday, 23 December 1725. This date lies in the fourth month of the Hijri year 1138 AH, which is Rabi Al-Thani of 1138 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1138/04/18 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 23 December 1725 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Rabi Al Thani 1138 AH to its equivalent Gregorian date.
وَجِا۟ىٓءَ يَوْمَئِذٍۭ بِجَهَنَّمَ ۚ يَوْمَئِذٍۢ يَتَذَكَّرُ ٱلْإِنسَٰنُ وَأَنَّىٰ لَهُ ٱلذِّكْرَىٰ
And hell is brought near that day; on that day man will remember, but how will the remembrance (then avail him)?
Surah Al-Fajr(89:23)