Well, the Hijri date 12 Rajab 1203 corresponds to the Gregorian date Tuesday, 7 April 1789. This date lies in the seventh month of the Hijri year 1203 AH, which is Rajab of 1203 AH. Both this Hijri and Gregorian date occur on the single day that is Tuesday without any doubt. The Arabic date 1203/07/12 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 7 April 1789 to its equivalent Arabic date.
The following is the conversion of the Arabic date 12 Rajab 1203 AH to its equivalent Gregorian date.
فَلَمَّا ٱسْتَيْـَٔسُوا۟ مِنْهُ خَلَصُوا۟ نَجِيًّۭا ۖ قَالَ كَبِيرُهُمْ أَلَمْ تَعْلَمُوٓا۟ أَنَّ أَبَاكُمْ قَدْ أَخَذَ عَلَيْكُم مَّوْثِقًۭا مِّنَ ٱللَّهِ وَمِن قَبْلُ مَا فَرَّطتُمْ فِى يُوسُفَ ۖ فَلَنْ أَبْرَحَ ٱلْأَرْضَ حَتَّىٰ يَأْذَنَ لِىٓ أَبِىٓ أَوْ يَحْكُمَ ٱللَّهُ لِى ۖ وَهُوَ خَيْرُ ٱلْحَٰكِمِينَ
So, When they despaired of (moving) him, they conferred together apart. The eldest of them said: Know ye not how your father took an undertaking from you in Allah's name and how ye failed in the case of Joseph aforetime? Therefore I shall not go forth from the land until my father giveth leave or Allah judgeth for me. He is the Best of Judges.
Surah Yusuf(12:80)