Can we observe fasting on the days of eid?
The days of eid come on top of the list of the days when fasting is prohibited. It is makruh tahrimi to fast on the first day of eid al-fitr and all four days of eid al-adha (Mawsili, al-Ikhtiyar, I, 395-396; Ibn Abidin, Radd al-Muhtar, III, 336). The reason why it is unliked and forbidden to fast on these days is because eid days are for eating, drinking and enjoyment. Eid al-fitr is considered as “a general iftar feast” offered after one-month fasting performed for the sake of Allah (swt). The first day of eid al-fitr is like the iftar of one-month Ramadan fasting. To fast on such a mass iftar day is considered as not attending to the symbolic feast of Allah (swt) and this is obviously unrespectful. The days of eid al-adha when sacrifices are made for the sake of Allah (swt) are also days of feast. The Prophet Muhammad (saw) stated that tashreeq days are for eating, drinking and praising Allah (swt) (Bukhari, Sawm, 66-67; Abu Dawud, Sawm, 49).
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS,