Well, the Hijri date 18 Ramadan 1421 corresponds to the Gregorian date Thursday, 14 December 2000. This date lies in the ninth month of the Hijri year 1421 AH, which is Ramadan of 1421 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1421/09/18 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 14 December 2000 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Ramadan 1421 AH to its equivalent Gregorian date.
لَّهُۥ مَقَالِيدُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۗ وَٱلَّذِينَ كَفَرُوا۟ بِـَٔايَٰتِ ٱللَّهِ أُو۟لَٰٓئِكَ هُمُ ٱلْخَٰسِرُونَ
His are the keys of the heavens and the earth, and they who disbelieve the revelations of Allah - such are they who are the losers.
Surah Az-Zumar(39:63)