Well, the Hijri date 8 Rabi Al Thani 1398 corresponds to the Gregorian date Friday, 17 March 1978. This date lies in the fourth month of the Hijri year 1398 AH, which is Rabi Al-Thani of 1398 AH. Both this Hijri and Gregorian date occur on the single day that is Friday without any doubt. The Arabic date 1398/04/08 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 17 March 1978 to its equivalent Arabic date.
The following is the conversion of the Arabic date 8 Rabi Al Thani 1398 AH to its equivalent Gregorian date.
كَذَٰلِكَ أَرْسَلْنَٰكَ فِىٓ أُمَّةٍۢ قَدْ خَلَتْ مِن قَبْلِهَآ أُمَمٌۭ لِّتَتْلُوَا۟ عَلَيْهِمُ ٱلَّذِىٓ أَوْحَيْنَآ إِلَيْكَ وَهُمْ يَكْفُرُونَ بِٱلرَّحْمَٰنِ ۚ قُلْ هُوَ رَبِّى لَآ إِلَٰهَ إِلَّا هُوَ عَلَيْهِ تَوَكَّلْتُ وَإِلَيْهِ مَتَابِ
Thus We send thee (O Muhammad) unto a nation, before whom other nations have passed away, that thou mayst recite unto them that which We have inspired in thee, while they are disbelievers in the Beneficent. Say: He is my Lord; there is no Allah save Him. In Him do I put my trust and unto Him is my recourse.
Surah Ar-Ra'd(13:30)