Well, the Hijri date 21 Shaban 1337 corresponds to the Gregorian date Wednesday, 21 May 1919. This date lies in the eighth month of the Hijri year 1337 AH, which is Shaban of 1337 AH. Both this Hijri and Gregorian date occur on the single day that is Wednesday without any doubt. The Arabic date 1337/08/21 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 21 May 1919 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Shaban 1337 AH to its equivalent Gregorian date.
ٱلَّذِينَ قَالُوٓا۟ إِنَّ ٱللَّهَ عَهِدَ إِلَيْنَآ أَلَّا نُؤْمِنَ لِرَسُولٍ حَتَّىٰ يَأْتِيَنَا بِقُرْبَانٍۢ تَأْكُلُهُ ٱلنَّارُ ۗ قُلْ قَدْ جَآءَكُمْ رُسُلٌۭ مِّن قَبْلِى بِٱلْبَيِّنَٰتِ وَبِٱلَّذِى قُلْتُمْ فَلِمَ قَتَلْتُمُوهُمْ إِن كُنتُمْ صَٰدِقِينَ
(The same are) those who say: Lo! Allah hath charged us that we believe not in any messenger until he bring us an offering which fire (from heaven) shall devour. Say (unto them, O Muhammad): Messengers came unto you before me with miracles, and with that (very miracle) which ye describe. Why then did ye slay them? (Answer that) if ye are truthful!
Surah Aal-i-Imraan(3:183)