Well, the Hijri date 27 Rajab 1400 corresponds to the Gregorian date Tuesday, 10 June 1980. This date lies in the seventh month of the Hijri year 1400 AH, which is Rajab of 1400 AH. Both this Hijri and Gregorian date occur on the single day that is Tuesday without any doubt. The Arabic date 1400/07/27 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 10 June 1980 to its equivalent Arabic date.
The following is the conversion of the Arabic date 27 Rajab 1400 AH to its equivalent Gregorian date.
وَإِذْ يُرِيكُمُوهُمْ إِذِ ٱلْتَقَيْتُمْ فِىٓ أَعْيُنِكُمْ قَلِيلًۭا وَيُقَلِّلُكُمْ فِىٓ أَعْيُنِهِمْ لِيَقْضِىَ ٱللَّهُ أَمْرًۭا كَانَ مَفْعُولًۭا ۗ وَإِلَى ٱللَّهِ تُرْجَعُ ٱلْأُمُورُ
And when He made you (Muslims), when ye met (them), see them with your eyes as few, and lessened you in their eyes, (it was) that Allah might conclude a thing that must be done. Unto Allah all things are brought back.
Surah Al-Anfaal(8:44)