Well, the Hijri date 20 Jumada Al Oula 1230 corresponds to the Gregorian date Saturday, 29 April 1815. This date lies in the fifth month of the Hijri year 1230 AH, which is Jumada Al-Awwal of 1230 AH. Both this Hijri and Gregorian date occur on the single day that is Saturday without any doubt. The Arabic date 1230/05/20 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 29 April 1815 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Jumada Al Oula 1230 AH to its equivalent Gregorian date.
وَمَن يُشَاقِقِ ٱلرَّسُولَ مِنۢ بَعْدِ مَا تَبَيَّنَ لَهُ ٱلْهُدَىٰ وَيَتَّبِعْ غَيْرَ سَبِيلِ ٱلْمُؤْمِنِينَ نُوَلِّهِۦ مَا تَوَلَّىٰ وَنُصْلِهِۦ جَهَنَّمَ ۖ وَسَآءَتْ مَصِيرًا
And whoso opposeth the messenger after the guidance (of Allah) hath been manifested unto him, and followeth other than the believer's way, We appoint for him that unto which he himself hath turned, and expose him unto hell - a hapless journey's end!
Surah An-Nisaa(4:115)