Well, the Hijri date 14 Muharram 1407 corresponds to the Gregorian date Thursday, 18 September 1986. This date lies in the first month of the Hijri year 1407 AH, which is Muharram of 1407 AH. Both this Hijri and Gregorian date occur on the single day that is Thursday without any doubt. The Arabic date 1407/01/14 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 18 September 1986 to its equivalent Arabic date.
The following is the conversion of the Arabic date 14 Muharram 1407 AH to its equivalent Gregorian date.
وَلَقَدْ عَهِدْنَآ إِلَىٰٓ ءَادَمَ مِن قَبْلُ فَنَسِىَ وَلَمْ نَجِدْ لَهُۥ عَزْمًۭا
And verily We made a covenant of old with Adam, but he forgot, and We found no constancy in him.
Surah Taa-Haa(20:115)