The following conditions must be met for the Friday prayer to be valid:

1. Its time must have begun. Because it is an obligatory prayer, the condition of entering its appointed time applies just as it does for the other prescribed prayers; therefore it is not valid before its time nor after it. Allah the Exalted says, “Indeed, prayer has been enjoined upon the believers at fixed times” (Qur’an 4:103). Performing it after the sun has passed the zenith is the preferred and safer course, for that is when the Messenger of Allah ﷺ most often performed it. Offering it before the zenith is a matter of scholarly dispute, whereas its latest permissible time is the end of the period for the Zuhr prayer—on this there is no disagreement.

2. The congregants must be permanent residents of dwellings that are customarily built with solid materials; hence it is not valid for people who live in tents or felt shelters and who usually move from place to place in search of rainfall, transporting their homes with them. Such nomadic Arabs lived around Medina, yet the Prophet ﷺ did not command them to observe the Friday prayer.

Whoever joins the imam and catches one rak‘ah of the Friday prayer completes it as Friday, based on the marfūʿ report from Abu Hurayrah: “Whoever catches one rak‘ah of the Friday prayer has caught the whole prayer,” related by al-Bayhaqī; its original narration is found in the two Ṣaḥīḥs.

If he joins after less than a rak‘ah—namely, the imam has already raised his head from the second rak‘ah before he entered the prayer—he has missed the Friday prayer. He therefore joins the imam with the intention of praying Zuhr; when the imam concludes, he rises and completes it as Zuhr.