1 Fiqh of Ramadan: Moon Sighting - Global vs Local vs Calculations

Shaykh ul Islam Ibn Taymiyyah states:

“The sighting [of the hilal] differs according to the difference in east and west. Undoubtedly, when it is sighted in the East, it MUST be sighted in the West, but not vice versa because the sunset is delayed further in the West than in the East. Thus, when it is sighted, it increases in light and distance from the Sun and its rays during the sunset [of the West]. It is then more likely to be sighted. This is not necessarily the case however if it was sighted in the West, because the reason it was sighted could have been the delay in the sunset in their (the Westerners’) [area], and thus it increased in distance and illumination, whereas during the sunset in the East, it was closer.” (Majmoo’ Fatawa Ibn Taymiyyah, vol. 25, pg. 98)