Well, the Hijri date 20 Rajab 1511 corresponds to the Gregorian date Thursday, 12 February 2088. This date lies in the seventh month of the Hijri year 1511 AH, which is Rajab of 1511 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1511/07/20 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 12 February 2088 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Rajab 1511 AH to its equivalent Gregorian date.
وَلِلَّهِ غَيْبُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۚ وَمَآ أَمْرُ ٱلسَّاعَةِ إِلَّا كَلَمْحِ ٱلْبَصَرِ أَوْ هُوَ أَقْرَبُ ۚ إِنَّ ٱللَّهَ عَلَىٰ كُلِّ شَىْءٍۢ قَدِيرٌۭ
And unto Allah belongeth the Unseen of the heavens and the earth, and the matter of the Hour (of Doom) is but as a twinkling of the eye, or it is nearer still. Lo! Allah is Able to do all things.
Surah An-Nahl(16:77)