Well, the Hijri date 18 Rabi Al Thani 1406 corresponds to the Gregorian date Monday, 30 December 1985. This date lies in the fourth month of the Hijri year 1406 AH, which is Rabi Al-Thani of 1406 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1406/04/18 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 30 December 1985 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Rabi Al Thani 1406 AH to its equivalent Gregorian date.
إِنْ هِىَ إِلَّآ أَسْمَآءٌۭ سَمَّيْتُمُوهَآ أَنتُمْ وَءَابَآؤُكُم مَّآ أَنزَلَ ٱللَّهُ بِهَا مِن سُلْطَٰنٍ ۚ إِن يَتَّبِعُونَ إِلَّا ٱلظَّنَّ وَمَا تَهْوَى ٱلْأَنفُسُ ۖ وَلَقَدْ جَآءَهُم مِّن رَّبِّهِمُ ٱلْهُدَىٰٓ
They are but names which ye have named, ye and your fathers, for which Allah hath revealed no warrant. They follow but a guess and that which (they) themselves desire. And now the guidance from their Lord hath come unto them.
Surah An-Najm(53:23)
Sahih al-Bukhari
Menstrual Periods
Chapter: If a woman gets her menses after Tawaf-al-Ifada
Narrated Ibn `Abbas:
A woman is allowed to leave (go back home) if she gets menses (after Tawaf-Al-Ifada). Ibn `Umar formerly used to say that she should not leave but later on I heard him saying, "She may leave, since Allah's Messenger (ﷺ) gave them the permission to leave (after Tawaf-Al-Ifada)."
Sahih al-Bukhari 329, 330