Those who argue that a single sighting does not apply to every region—most Shāfiʿī jurists, for example—differ among themselves. Some set the limit at the distance that allows a traveller to shorten the prayer, while others tie it to the divergence of horizons, such as between the Ḥijāz and Greater Syria, or between Iraq and Khurāsān. Both views are weak: the legal travel distance has nothing to do with the crescent, and as for “climatic zones,” who can even define their exact borders? These two positions are faulty on two counts. First, visibility varies according to east and west. Whenever the crescent is sighted in the East, it must necessarily be visible in the West—and not the other way around—because sunset in western lands occurs later than in eastern ones. If the moon has already been seen in the East, by the time the sun sets in the West the crescent will be farther from the sun and brighter, making it even easier to see. The reverse is not true: a sighting in the West may be due to the later sunset there, which gives the moon more time to distance itself and increase in brightness, whereas when the sun set earlier in the East the moon was still too close to it. Moreover, once the crescent is seen in the West, it has already set for the people of the East. This is plainly observable with the setting of the sun, the crescent, and all the other stars. Thus, when Maghrib time enters in the West it has already entered in the East, but not vice-versa. The same applies to rising: if a celestial body rises in the West, it must have risen earlier in the East, and not the reverse. In short, the rising and setting of the stars take place first in the East.