Well, the Hijri date 1 Dhul Qidah 1406 corresponds to the Gregorian date Tuesday, 8 July 1986. This date lies in the eleventh month of the Hijri year 1406 AH, which is Dhu Al-Qidah of 1406 AH. Both this Hijri and Gregorian date occur on the single day that is Tuesday without any doubt. The Arabic date 1406/11/01 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 8 July 1986 to its equivalent Arabic date.
The following is the conversion of the Arabic date 1 Dhul Qidah 1406 AH to its equivalent Gregorian date.
سَيَقُولُونَ ثَلَٰثَةٌۭ رَّابِعُهُمْ كَلْبُهُمْ وَيَقُولُونَ خَمْسَةٌۭ سَادِسُهُمْ كَلْبُهُمْ رَجْمًۢا بِٱلْغَيْبِ ۖ وَيَقُولُونَ سَبْعَةٌۭ وَثَامِنُهُمْ كَلْبُهُمْ ۚ قُل رَّبِّىٓ أَعْلَمُ بِعِدَّتِهِم مَّا يَعْلَمُهُمْ إِلَّا قَلِيلٌۭ ۗ فَلَا تُمَارِ فِيهِمْ إِلَّا مِرَآءًۭ ظَٰهِرًۭا وَلَا تَسْتَفْتِ فِيهِم مِّنْهُمْ أَحَدًۭا
(Some) will say: They were three, their dog the fourth, and (some) say: Five, their dog the sixth, guessing at random; and (some) say: Seven, and their dog the eighth. Say (O Muhammad): My Lord is Best Aware of their number. None knoweth them save a few. So contend not concerning them except with an outward contending, and ask not any of them to pronounce concerning them.
Surah Al-Kahf(18:22)