The difference of the timing of Muslims' religious festivals

Q 1: What is the ruling on the difference of setting the beginning of Muslims' religious festivals like `Eid-ul-Fitr (the Festival of Breaking the Fast), and `Eid-ul-Adha (the Festival of the Sacrifice)? It is worthy to mention that this results in people fasting a day which is prohibited to fast such as the day of `Eid-ul-Fitr or breaking their fast on a day that should be observed. I need a decisive answer regarding this matter please. If Islam rejects this difference, how can Muslim festivals be unified?

A: Scholars agree that the sighting of the crescent causes differences. However, they held different opinions regarding (Part No. 10; Page No. 101) whether the difference in sighting the moon matters or not in the beginning and the end of Ramadan. Some Fuqaha' (Muslim jurists) held the opinion that the difference in sighting the moon does matter in the beginning and end of Ramadan while others see that it does not. Each group quotes evidence from the Qur’an and Sunnah, and sometimes they quote the same text, such as when they both quote the following Ayah (Qur'anic verse): So whoever of you sights (the crescent on the first night of) the month (of Ramadan i.e. is present at his home), he must observe Saum (fasts) that month and They ask you (O Muhammad صلى الله عليه وسلم) about the new moons. Say: These are signs to mark fixed periods of time for mankind They also quote the Prophet's (peace be upon him) Hadith, Start fasting on seeing it (the new moon of Ramadan), and stop fasting on seeing it (the new moon of Shawwal). This is due to the different understandings of the texts, and different ways in which each group derives evidence from them. To sum up, issues which have no reference in the Qur'an or Sunnah are open to Ijtihad (juristic effort to infer expert legal rulings), and the Fuqaha' held different views in its regard in the past and the present. There is no blame on the people of any country, if they did not witness the moon on the night before the thirtieth, to follow the sighting of the moon in another territory rather than theirs when sighting the moon is confirmed. In case they disagree, they should follow the opinion of their Muslim ruler for his judgment will end the argument and therefore, the Ummah (nation) should follow it. In case the ruler is not a Muslim, they should follow the decision taken by (Part No. 10; Page No. 102) the concerned Islamic center in their country so as to unify the beginning of Ramadan and Salat-ul-`Eid (the Festival Prayer) in their country.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.