Well, the Hijri date 14 Rabi Al Thani 1228 corresponds to the Gregorian date Thursday, 15 April 1813. This date lies in the fourth month of the Hijri year 1228 AH, which is Rabi Al-Thani of 1228 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1228/04/14 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 15 April 1813 to its equivalent Arabic date.
The following is the conversion of the Arabic date 14 Rabi Al Thani 1228 AH to its equivalent Gregorian date.
قَالُوا۟ بَل لَّمْ تَكُونُوا۟ مُؤْمِنِينَ
They answer: Nay, but ye (yourselves) were not believers.
Surah As-Saaffaat(37:29)