Name taken from Verse 1 where there is a mention of “Al Qamar”.
Ù¡ اقْتَرَبَتِ السَّاعَØ©ُ ÙˆَانْØ´َÙ‚َّ الْÙ‚َÙ…َرُ1
The Hour has come near, and the moon has splitBut It does not mean that this name is the actual topic discussed in the whole Surah. It is just a reference and mark/symbol to distinguish this Surah from others as is with most other Surahs of Quran. While there are diversified topics discussed in these Surahs.