Well, the Hijri date 21 Dhul Hijjah 1400 corresponds to the Gregorian date Thursday, 30 October 1980. This date lies in the twelfth month of the Hijri year 1400 AH, which is Dhu Al-Hijjah of 1400 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1400/12/21 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 October 1980 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Dhul Hijjah 1400 AH to its equivalent Gregorian date.
ذَٰلِكَ ٱلَّذِى يُبَشِّرُ ٱللَّهُ عِبَادَهُ ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّٰلِحَٰتِ ۗ قُل لَّآ أَسْـَٔلُكُمْ عَلَيْهِ أَجْرًا إِلَّا ٱلْمَوَدَّةَ فِى ٱلْقُرْبَىٰ ۗ وَمَن يَقْتَرِفْ حَسَنَةًۭ نَّزِدْ لَهُۥ فِيهَا حُسْنًا ۚ إِنَّ ٱللَّهَ غَفُورٌۭ شَكُورٌ
This it is which Allah announceth unto His bondmen who believe and do good works. Say (O Muhammad, unto mankind): I ask of you no fee therefor, save lovingkindness among kinsfolk. And whoso scoreth a good deed We add unto its good for him. Lo! Allah is Forgiving, Responsive.
Surah Ash-Shura(42:23)