Evidence from the Quran and the Sunnah clearly demonstrates that the Eids are distinctive features for every nation. Allah said:
"To every people we have appointed rites (of sacrifice) that they must observe."
[Noble Quran 22:67]
From authentic hadiths that are cited above and subsequently, it is concluded that the Muslims have only three Eid days, a weekly Eid every Friday, and two annual Eids: al-Fitr and al-Adha.
Thus, the Eids are purely religious occasions for the Muslims. They are the only holidays in Islam, and were granted to the Muslims by Allah. This indicates His great love and mercy toward those who adhere to His blessed religion: Islam.
And when Allah, the most Generous, grants something, he grants it complete and perfect. Thus, He granted us the Eids, as well as instructions for celebrating them.
It becomes clear then that:
Allah alone has the right to prescribe Eids and to set their dates.
Allah alone has the right to prescribe the manner of celebrating them.