Aisha reported that the Prophet ﷺ said, "The fast is on the day you all fast, the breaking of the fast is on the day you all break it, and the sacrifice is on the day you all offer the sacrifice."
أن النبي ﷺ قال: الصوم يوم تصومون، والفطر يوم تفطرون، والأضحى يوم تضحون.
Tirmidhi (697) narrated it from Muhammad bin Ismail, who said, Ibrahim bin Munzir narrated to us, who said, Ishaq bin Jafar bin Muhammad narrated to us, who said, Abdullah bin Jafar narrated to me, from Uthman bin Muhammad Akhnasi, from Saeed Maqburi, from Abu Hurairah, and he mentioned it. Tirmidhi said, "Hasan gharib."I say, its chain is hasan due to the discussion regarding Uthman bin Muhammad Akhnasi. Ibn Main authenticated him, while Nasai said, he is not that strong, and Ali bin Madini qualified this by noting that he narrated objectionable hadiths from Saeed bin Musayab, from Abu Hurairah. Ibn Hibban mentioned him in Thiqat, and the summary regarding him is that his hadith is hasan as long as he is not narrating from Saeed bin Musayab.This hadith has other routes. Among them is what Abu Dawud (2324) narrated from Muhammad bin Ubayd, who said, Hammad narrated to us in the hadith of Ayub, from Muhammad bin Munkadir, from Abu Hurairah, mentioning the Prophet ﷺ, in which he said, "Your Fitr is the day you break the fast, and your Adha is the day you sacrifice, every part of Arafah is a place of standing, every part of Mina is a place of sacrifice, every ravine of Makkah is a place of sacrifice, and all of Jam is a place of standing." So he added the final phrases to it. Muhammad bin Munkadir did not meet Abu Hurairah according to the correct view, as stated by Yahya bin Main and Abu Zura. Munziri said, he narrated from Abu Hurairah but did not hear from him.Among them also is what Ibn Majah (1660) narrated from Muhammad bin Umar Muqri, who said, Ishaq bin Isa narrated to us, who said, Hammad bin Zayd narrated to us, from Ayub, from Muhammad bin Sirin, from Abu Hurairah, who said, "Fitr is the day you break the fast, and Adha is the day you sacrifice." In this chain is Ibn Majah's teacher Muhammad bin Umar Muqri, about whom the Hafiz said, "He is unknown, and he may be Muhammad bin Abu Umar Dawri." Moreover, he diverged by making it from Ayub from Muhammad bin Sirin, while the correct version is that it is from Muhammad bin Munkadir, as the trustworthy narrators reported it.Among them also is a version placed in the musnad of Ayesha. Tirmidhi (802) and Daraqutni (2447) both narrated it through the route of Yahya bin Yaman, from Mamar, from Muhammad bin Munkadir, from Ayesha. Abu Hisham said, I think he attributed it to the Prophet as marfu. He said, "Fitr is the day people break the fast, and Adha is the day people sacrifice." Tirmidhi said, I asked Muhammad, I said to him, did Muhammad bin Munkadir hear from Ayesha? He said, Yes, he says in his hadith, I heard Ayesha. Tirmidhi said, "This is a hadith hasan gharib sahih from this angle."I say, rather its chain is daif due to the discussion regarding Yahya bin Yaman, and its divergence from the trustworthy narrators who placed this hadith in the musnad of Abu Hurairah. However, there is disagreement over whether it is marfu or mawquf, as Daraqutni mentioned in his book Ilal (1867).The summary is that the hadith is hasan by the chain that Tirmidhi presented, and the other chains strengthen it, except for a few minor phrases that have not been established.The meaning of the hadith is that fasting and breaking the fast are to be observed with the community and the majority of people, as Tirmidhi stated. So no one is permitted to break away from the community in the beginning of the fast or the two eids of Fitr and Adha.Sindi said, "It appears the meaning is that these matters are not left to individuals, and individuals do not have the right to act independently in them. Rather, the matter rests with the leader and the community, and it is obligatory upon individuals to follow the leader and the community. Accordingly, if someone sees the crescent moon and the leader rejects his testimony, none of these matters should be established as binding upon him, and he must follow the community in that." End of quote.It has also been said that he may fast or break his fast if he sees the crescent moon, except that he should not repeat the eid prayer except with the people.