Well, the Hijri date 20 Rabi Al Thani 1261 corresponds to the Gregorian date Sunday, 27 April 1845. This date lies in the fourth month of the Hijri year 1261 AH, which is Rabi Al-Thani of 1261 AH. Both this Hijri and Gregorian date occur on the single day that is Sunday without any doubt. The Arabic date 1261/04/20 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 27 April 1845 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Rabi Al Thani 1261 AH to its equivalent Gregorian date.
وَلِلَّهِ ٱلْأَسْمَآءُ ٱلْحُسْنَىٰ فَٱدْعُوهُ بِهَا ۖ وَذَرُوا۟ ٱلَّذِينَ يُلْحِدُونَ فِىٓ أَسْمَٰٓئِهِۦ ۚ سَيُجْزَوْنَ مَا كَانُوا۟ يَعْمَلُونَ
Allah's are the fairest names. Invoke Him by them. And leave the company of those who blaspheme His names. They will be requited what they do.
Surah Al-A'raaf(7:180)