Well, the Hijri date 22 Safar 1287 corresponds to the Gregorian date Monday, 23 May 1870. This date lies in the second month of the Hijri year 1287 AH, which is Safar of 1287 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1287/02/22 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 23 May 1870 to its equivalent Arabic date.
The following is the conversion of the Arabic date 22 Safar 1287 AH to its equivalent Gregorian date.
وَيَسْتَعْجِلُونَكَ بِٱلْعَذَابِ وَلَن يُخْلِفَ ٱللَّهُ وَعْدَهُۥ ۚ وَإِنَّ يَوْمًا عِندَ رَبِّكَ كَأَلْفِ سَنَةٍۢ مِّمَّا تَعُدُّونَ
And they will bid thee hasten on the Doom, and Allah faileth not His promise, but lo! a Day with Allah is as a thousand years of what ye reckon.
Surah Al-Hajj(22:47)