Well, the Hijri date 15 Rabi Al Thani 1239 corresponds to the Gregorian date Thursday, 18 December 1823. This date lies in the fourth month of the Hijri year 1239 AH, which is Rabi Al-Thani of 1239 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1239/04/15 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 18 December 1823 to its equivalent Arabic date.
The following is the conversion of the Arabic date 15 Rabi Al Thani 1239 AH to its equivalent Gregorian date.
وَمَنْ أَحْسَنُ قَوْلًۭا مِّمَّن دَعَآ إِلَى ٱللَّهِ وَعَمِلَ صَٰلِحًۭا وَقَالَ إِنَّنِى مِنَ ٱلْمُسْلِمِينَ
And who is better in speech than him who prayeth unto his Lord and doeth right, and saith: Lo! I am of those who are muslims (surrender unto Him).
Surah Fussilat(41:33)