Well, the Hijri date 18 Ramadan 1405 corresponds to the Gregorian date Thursday, 6 June 1985. This date lies in the ninth month of the Hijri year 1405 AH, which is Ramadan of 1405 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1405/09/18 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 6 June 1985 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Ramadan 1405 AH to its equivalent Gregorian date.
وَمِنْ ءَايَٰتِهِۦ خَلْقُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ وَمَا بَثَّ فِيهِمَا مِن دَآبَّةٍۢ ۚ وَهُوَ عَلَىٰ جَمْعِهِمْ إِذَا يَشَآءُ قَدِيرٌۭ
And of His portents is the creation of the heaven and the earth, and of whatever beasts He hath dispersed therein. And He is Able to gather them when He will.
Surah Ash-Shura(42:29)
Sahih al-Bukhari
Retiring to a Mosque for Remembrance of Allah (I'tikaf)
Chapter: Tents in mosque.
Narrated `Aisha:
The Prophet (ﷺ) intended to practice I`tikaf and when he reached the place where he intended to perform I`tikaf, he saw some tents, the tents of `Aisha, Hafsa and Zainab. So, he said, "Do you consider that they intended to do righteousness by doing this?" And then he went away and did not perform I`tikaf (in Ramadan) but performed it in the month of Shawwal for ten days.
Sahih al-Bukhari 2034