Well, the Hijri date 20 Shaban 1274 corresponds to the Gregorian date Sunday, 4 April 1858. This date lies in the eighth month of the Hijri year 1274 AH, which is Shaban of 1274 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1274/08/20 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 4 April 1858 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Shaban 1274 AH to its equivalent Gregorian date.
وَمَنْ أَظْلَمُ مِمَّن ذُكِّرَ بِـَٔايَٰتِ رَبِّهِۦ فَأَعْرَضَ عَنْهَا وَنَسِىَ مَا قَدَّمَتْ يَدَاهُ ۚ إِنَّا جَعَلْنَا عَلَىٰ قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِىٓ ءَاذَانِهِمْ وَقْرًۭا ۖ وَإِن تَدْعُهُمْ إِلَى ٱلْهُدَىٰ فَلَن يَهْتَدُوٓا۟ إِذًا أَبَدًۭا
And who doth greater wrong than he who hath been reminded of the revelations of his Lord, yet turneth away from them and forgetteth what his hands send forward (to the Judgment)? Lo! on their hearts We have placed coverings so that they understand not, and in their ears a deafness. And though thou call them to the guidance, in that case they can never be led aright.
Surah Al-Kahf(18:57)