Well, the Hijri date 13 Muharram 1399 corresponds to the Gregorian date Wednesday, 13 December 1978. This date lies in the first month of the Hijri year 1399 AH, which is Muharram of 1399 AH. Both this Hijri and Gregorian date occur on the single day that is Wednesday without any doubt. The Arabic date 1399/01/13 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 13 December 1978 to its equivalent Arabic date.
The following is the conversion of the Arabic date 13 Muharram 1399 AH to its equivalent Gregorian date.
يَوْمَ يُحْمَىٰ عَلَيْهَا فِى نَارِ جَهَنَّمَ فَتُكْوَىٰ بِهَا جِبَاهُهُمْ وَجُنُوبُهُمْ وَظُهُورُهُمْ ۖ هَٰذَا مَا كَنَزْتُمْ لِأَنفُسِكُمْ فَذُوقُوا۟ مَا كُنتُمْ تَكْنِزُونَ
On the day when it will (all) be heated in the fire of hell, and their foreheads and their flanks and their backs will be branded therewith (and it will be said unto them): Here is that which ye hoarded for yourselves. Now taste of what ye used to hoard.
Surah At-Tawba(9:35)
