Well, the Hijri date 20 Muharram 1398 corresponds to the Gregorian date Friday, 30 December 1977. This date lies in the first month of the Hijri year 1398 AH, which is Muharram of 1398 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1398/01/20 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 30 December 1977 to its equivalent Arabic date.
The following is the conversion of the Arabic date 20 Muharram 1398 AH to its equivalent Gregorian date.
وَإِذَا تُتْلَىٰ عَلَيْهِمْ ءَايَاتُنَا بَيِّنَٰتٍۢ ۙ قَالَ ٱلَّذِينَ لَا يَرْجُونَ لِقَآءَنَا ٱئْتِ بِقُرْءَانٍ غَيْرِ هَٰذَآ أَوْ بَدِّلْهُ ۚ قُلْ مَا يَكُونُ لِىٓ أَنْ أُبَدِّلَهُۥ مِن تِلْقَآئِ نَفْسِىٓ ۖ إِنْ أَتَّبِعُ إِلَّا مَا يُوحَىٰٓ إِلَىَّ ۖ إِنِّىٓ أَخَافُ إِنْ عَصَيْتُ رَبِّى عَذَابَ يَوْمٍ عَظِيمٍۢ
And when Our clear revelations are recited unto them, they who look not for the meeting with Us say: Bring a Lecture other than this, or change it. Say (O Muhammad): It is not for me to change it of my accord. I only follow that which is inspired in me. Lo! if I disobey my Lord I fear the retribution of an awful Day.
Surah Yunus(10:15)