Q8. Is this opinion not going to cause disunity amongst the Muslims?

If someone adopts this view such that Ramaḍhān ends while the Muslims in his country are still fasting, then he should not eat in public to avoid conflict and maintain unity. This was the view held by Ash-Shāfi’ē raḥimahullāh and is also a Riwāyah from Aḥmad. 🔺Note: this is not an issue that Muslims should be fighting over. Sheikh ibn Bāz raḥimahullāh said: “Fast when you see it and break your fast when you see it', this [statement of the Prophet ﷺ] encompasses the whole Ummah, so if it's possible for them to fast based on the sighting of Saudi Arabia for example, or the sighting of another Islamic country that rules by Shari’ah law and implements Allāhs commands in terms of moon sighting via witness testimonials and not based on calculations, then there's nothing wrong with that. This is better; that they all fast based on one sighting, due to the general evidences. But if this is not possible, due to the regions and countries being far apart, such that every country fasts based on its own sighting, then this is okay.” Q9. Why can't we just rely on astronomical calculations? The number of days within a lunar month must not be predetermined in advance, as we have been instructed to establish the start and end of every month, including Ramaḍhān, based on the sighting of the new moon. The permanent committee issued a verdict (fatwa: 386) that: “Relying on astronomical calculations to determine the duration of months in a lunar calendar as it relates to the start and end dates of religious rites, such as Ramaḍhā, Ḥajj, etc, without basing that on moon sighting, is an innovated practice, devoid of any good, and it has no basis in the Sharī‘ah.” Q10. Are we allowed to use a telescope to look for the crescent? Sheikh ’Uthaymīn raḥimahullāh mentioned that it's permissible, but not necessary, because what's apparent from the Sunnah is that we should rely on ordinary sighting and nothing else. But if telescopes are used and the moon is sighted by a trustworthy person, then this sighting is acted upon...In the past, people used to climb up minarets on the night of the 29th to look for the crescent. [Fatāwā ‘Ulamā’ Al-Balad Al-Ḥarām (p. 192, 193)]