Well, the Hijri date 21 Shawwal 1222 corresponds to the Gregorian date Monday, 21 December 1807. This date lies in the tenth month of the Hijri year 1222 AH, which is Shawwal of 1222 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1222/10/21 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 21 December 1807 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Shawwal 1222 AH to its equivalent Gregorian date.
وَإِذْ قَالَتْ أُمَّةٌۭ مِّنْهُمْ لِمَ تَعِظُونَ قَوْمًا ۙ ٱللَّهُ مُهْلِكُهُمْ أَوْ مُعَذِّبُهُمْ عَذَابًۭا شَدِيدًۭا ۖ قَالُوا۟ مَعْذِرَةً إِلَىٰ رَبِّكُمْ وَلَعَلَّهُمْ يَتَّقُونَ
And when a community among them said: Why preach ye to a folk whom Allah is about to destroy or punish with an awful doom, they said: In order to be free from guilt before your Lord, and that haply they may ward off (evil).
Surah Al-A'raaf(7:164)