It is recommended to recite Surat al-Kahf completely the night before Friday, and it is also recommended to do so Friday itself, before Maghrib time. Ibn Abidin said, �And it is best to do so early on Friday, in order to rush to the good and to avoid forgetting. � [Ibn Abidin, Radd al-Muhtar, �Bab al-Jumu`ah�]
The evidence for it being recommended includes the hadith related by Hakim and Bayhaqi, from Abu Sa`id (Allah be pleased with him), �Whoever recites Surat al-Kahf on Friday, light shall shine forth for him between the two...
