Well, the Hijri date 21 Rabi Al Awwal 1377 corresponds to the Gregorian date Monday, 14 October 1957. This date lies in the third month of the Hijri year 1377 AH, which is Rabi Al-Awwal of 1377 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1377/03/21 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 14 October 1957 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Rabi Al Awwal 1377 AH to its equivalent Gregorian date.
أُو۟لَٰٓئِكَ ٱلَّذِينَ يَدْعُونَ يَبْتَغُونَ إِلَىٰ رَبِّهِمُ ٱلْوَسِيلَةَ أَيُّهُمْ أَقْرَبُ وَيَرْجُونَ رَحْمَتَهُۥ وَيَخَافُونَ عَذَابَهُۥٓ ۚ إِنَّ عَذَابَ رَبِّكَ كَانَ مَحْذُورًۭا
Those unto whom they cry seek the way of approach to their Lord, which of them shall be the nearest; they hope for His mercy and they fear His doom. Lo! the doom of thy Lord is to be shunned.
Surah Al-Israa(17:57)