Well, the Hijri date 21 Muharram 1440 corresponds to the Gregorian date Monday, 1 October 2018. This date lies in the first month of the Hijri year 1440 AH, which is Muharram of 1440 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1440/01/21 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 1 October 2018 to its equivalent Arabic date.
The following is the conversion of the Arabic date 21 Muharram 1440 AH to its equivalent Gregorian date.
إِنَّ ٱللَّهَ رَبِّى وَرَبُّكُمْ فَٱعْبُدُوهُ ۗ هَٰذَا صِرَٰطٌۭ مُّسْتَقِيمٌۭ
Lo! Allah is my Lord and your Lord, so worship Him. That is a straight path.
Surah Aal-i-Imraan(3:51)
Sahih al-Bukhari
Fighting for the Cause of Allah (Jihaad)
Chapter: Participation in Jihad with parent's permission
Narrated `Abdullah bin `Amr:
A man came to the Prophet (ﷺ) asking his permission to take part in Jihad. The Prophet (ﷺ) asked him, "Are your parents alive?" He replied in the affirmative. The Prophet (ﷺ) said to him, "Then exert yourself in their service."
Sahih al-Bukhari 3004