Well, the Hijri date 20 Shawwal 1402 corresponds to the Gregorian date Monday, 9 August 1982. This date lies in the tenth month of the Hijri year 1402 AH, which is Shawwal of 1402 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1402/10/20 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 9 August 1982 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Shawwal 1402 AH to its equivalent Gregorian date.
قَالُوا۟ يَٰنُوحُ قَدْ جَٰدَلْتَنَا فَأَكْثَرْتَ جِدَٰلَنَا فَأْتِنَا بِمَا تَعِدُنَآ إِن كُنتَ مِنَ ٱلصَّٰدِقِينَ
They said: O Noah! Thou hast disputed with us and multiplied disputation with us; now bring upon us that wherewith thou threatenest us, if thou art of the truthful.
Surah Hud(11:32)