The timings for prayers and months have to be precise that is correct but for example, what happens when the moon for Ramadan hasn't been sighted (it starts whe

The timings for prayers and months have to be precise that is correct but for example, what happens when the moon for Ramadan hasn't been sighted (it starts when the first crescent of the new moon is sighted). In that instance you would follow your neighbouring country. It is true that there are slight variations in the prayer timings between cities so hence when looking at the neighbouring country you would obviously choose the nearest city. This is the view and ruling of all 4 schools of jurisprudence within the Sunni sect. Bit of background on schools of thought and sects. Islam is split between Sunni Muslims and Shias. Sunnis make up the majority and within Sunni Muslims there are 4 schools of thought. The rulings between the schools differ based on interpretations of the Quran, Ahaadith (Prophetic sayings), consensus of the Prophet Muhammad's companions and deductive analogy. The 4 schools of thoughts are not sects, i.e. they consider each other to be Muslims, unlike Sunni Muslims who consider (most) Shia sects, Ahamdis et al to not be Muslim. An example of a difference in interpretation is the Quran instructs people to wash their faces, arms to the elbows, head and feet to ankles. Now does they include the ankles or not? Does the word "to" define a limit? Then different scholars from the schools of thoughts give their opinion, some say that it does based on certain linguistic evidences, eyewitness accounts of the Prophet Muhammed (p.b.u.h) actions or his sayings and hence that's how the rulings differ. Source - I am studying, alongside my professional career, Islamic sciences such as theology, jurisprudence, classical Arabic, Hadith and Quran exodus etc and hopefully graduate as an Islamic scholar soon!