Well, the Hijri date 18 Shaban 1409 corresponds to the Gregorian date Saturday, 25 March 1989. This date lies in the eighth month of the Hijri year 1409 AH, which is Shaban of 1409 AH. Both this Hijri and Gregorian date occur on the single day that is Saturday without any doubt. The Arabic date 1409/08/18 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 25 March 1989 to its equivalent Arabic date.
The following is the conversion of the Arabic date 18 Shaban 1409 AH to its equivalent Gregorian date.
أَمْ أَمِنتُمْ أَن يُعِيدَكُمْ فِيهِ تَارَةً أُخْرَىٰ فَيُرْسِلَ عَلَيْكُمْ قَاصِفًۭا مِّنَ ٱلرِّيحِ فَيُغْرِقَكُم بِمَا كَفَرْتُمْ ۙ ثُمَّ لَا تَجِدُوا۟ لَكُمْ عَلَيْنَا بِهِۦ تَبِيعًۭا
Or feel ye secure that He will not return you to that (plight) a second time, and send against you a hurricane of wind and drown you for your thanklessness, and then ye will not find therein that ye have any avenger against Us?
Surah Al-Israa(17:69)