Well, the Hijri date 21 Dhul Hijjah 1336 corresponds to the Gregorian date Thursday, 26 September 1918. This date lies in the twelfth month of the Hijri year 1336 AH, which is Dhu Al-Hijjah of 1336 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1336/12/21 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 26 September 1918 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Dhul Hijjah 1336 AH to its equivalent Gregorian date.
وَأَمَّا ثَمُودُ فَهَدَيْنَٰهُمْ فَٱسْتَحَبُّوا۟ ٱلْعَمَىٰ عَلَى ٱلْهُدَىٰ فَأَخَذَتْهُمْ صَٰعِقَةُ ٱلْعَذَابِ ٱلْهُونِ بِمَا كَانُوا۟ يَكْسِبُونَ
And as for Thamud, We gave them guidance, but they preferred blindness to the guidance, so the bolt of the doom of humiliation overtook them because of what they used to earn.
Surah Fussilat(41:17)