Well, the Hijri date 20 Muharram 1420 corresponds to the Gregorian date Thursday, 6 May 1999. This date lies in the first month of the Hijri year 1420 AH, which is Muharram of 1420 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1420/01/20 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 6 May 1999 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Muharram 1420 AH to its equivalent Gregorian date.
۞ إِلَيْهِ يُرَدُّ عِلْمُ ٱلسَّاعَةِ ۚ وَمَا تَخْرُجُ مِن ثَمَرَٰتٍۢ مِّنْ أَكْمَامِهَا وَمَا تَحْمِلُ مِنْ أُنثَىٰ وَلَا تَضَعُ إِلَّا بِعِلْمِهِۦ ۚ وَيَوْمَ يُنَادِيهِمْ أَيْنَ شُرَكَآءِى قَالُوٓا۟ ءَاذَنَّٰكَ مَا مِنَّا مِن شَهِيدٍۢ
Unto Him is referred (all) knowledge of the Hour. And no fruits burst forth from their sheaths, and no female carrieth or bringeth forth but with His knowledge. And on the day when He calleth unto them: Where are now My partners? they will say: We confess unto Thee, not one of us is a witness (for them).
Surah Fussilat(41:47)