It's not Friday, but this namesake phenomenon of Surah 89 corresponds to the recitation of two rak'aat recited aloud in the (*) Fajr service.
A surah named for this natural phenomenon starts with oaths "by the Ten Nights" and "By the Even and the Odd," and notes that Allah punished the pillar-building 'Aad-Iram people as well as the Thammud. Islamic sources claim that a "false" one of these is akin to the tail of a sirhan, a creature whose name is translated as "wolf" or "fox." In Egypt, rituals tied to this natural occurrence are preceded by drum-banging from a volunteer called the mesaharati. It's not Friday, but this namesake phenomenon of Surah 89 corresponds to the recitation of two rak'aat recited aloud in the (*) Fajr service. A verse in the Cow surah defines it using the visual distinction of white threads from black. The timing of suhoor meals is set with respect to, for 10 points, what general time, at which the muezzin's adhan contains the extra line "Prayer is better than sleep"?
A surah named for this natural phenomenon starts with oaths "by the Ten Nights" and "By the Even and the Odd," and notes that Allah punished the pillar-building 'Aad-Iram people as well as the Thammud.
dawn [or daybreak; or the first daylight; accept fajr until mention; prompt on morning; prompt on twilight; do NOT accept or prompt on "sunrise," "day," or "night"] 