Reading Surat al-Kahf on the night of Jumu’ah
The Prophet (sal Allahu alaihi wa sallam) said, “Whoever reads Surat al-Kahf on the night of Jumu’ah, will have a light that will stretch between him and the Ancient House (the Ka’bah).”
[Narrated by al-Daarimi, 3407. This Hadith was classed as Sahih by Shaykh al-Albaani in Saheeh al-Jaami, 6471]
Surat al-Kahf may be read during the night or the day of Jumu’ah.
The night of Jumu’ah starts from sunset on Thursday, and the day of Jumu’ah ends at sunset. Therefore the time for reading this surah extends from sunset on Thursday to sunset on Friday.
Al-Mannaawi (may Allah have mercy upon him) said: Al-Haafiz ibn Hajar (may Allah have mercy upon him) said in his Amaali: “In some reports it says ‘the day of Jumu’ah’ and in some reports it says ‘the night of Jumu’ah’. They may be reconciled by saying that what is meant is the day which includes the night and vice versa.” (Fayd al-Qadeer, 6/199)
Al-Mannaawi (may Allah have mercy upon him) also said: “It is recommended to read it during the day or night of Jumu’ah, as al-Shaafa’i (may Allaah have mercy on him) stated.” (Fayd al-Qadeer, 6/198)
And Allah knows best!