Well, the Hijri date 20 Shawwal 1397 corresponds to the Gregorian date Monday, 3 October 1977. This date lies in the tenth month of the Hijri year 1397 AH, which is Shawwal of 1397 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1397/10/20 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 3 October 1977 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Shawwal 1397 AH to its equivalent Gregorian date.
فَٱسْتَفْتِهِمْ أَهُمْ أَشَدُّ خَلْقًا أَم مَّنْ خَلَقْنَآ ۚ إِنَّا خَلَقْنَٰهُم مِّن طِينٍۢ لَّازِبٍۭ
Then ask them (O Muhammad): Are they stronger as a creation, or those (others) whom we have created? Lo! We created them of plastic clay.
Surah As-Saaffaat(37:11)