Well, the Hijri date 18 Shaban 1235 corresponds to the Gregorian date Tuesday, 30 May 1820. This date lies in the eighth month of the Hijri year 1235 AH, which is Shaban of 1235 AH. Both this Hijri and Gregorian date occur on the single day that is Tuesday without any doubt. The Arabic date 1235/08/18 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 30 May 1820 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Shaban 1235 AH to its equivalent Gregorian date.
فَإِنْ حَآجُّوكَ فَقُلْ أَسْلَمْتُ وَجْهِىَ لِلَّهِ وَمَنِ ٱتَّبَعَنِ ۗ وَقُل لِّلَّذِينَ أُوتُوا۟ ٱلْكِتَٰبَ وَٱلْأُمِّيِّۦنَ ءَأَسْلَمْتُمْ ۚ فَإِنْ أَسْلَمُوا۟ فَقَدِ ٱهْتَدَوا۟ ۖ وَّإِن تَوَلَّوْا۟ فَإِنَّمَا عَلَيْكَ ٱلْبَلَٰغُ ۗ وَٱللَّهُ بَصِيرٌۢ بِٱلْعِبَادِ
And if they argue with thee, (O Muhammad), say: I have surrendered my purpose to Allah and (so have) those who follow me. And say unto those who have received the Scripture and those who read not: Have ye (too) surrendered? If they surrender, then truly they are rightly guided, and if they turn away, then it is thy duty only to convey the message (unto them). Allah is Seer of (His) bondmen.
Surah Aal-i-Imraan(3:20)