In separate messages to Ayatollah Khamenei and Rouhani, Husein Kavazovic also wished the Iranian nation and all Muslims in the world health, peace, and success.
Eid al-Adha is one of Islam's holiest festivals celebrated annually around the world and an official holiday in Muslim-majority countries.
In the Islamic calendar, Eid al-Adha occurs on the 10th day of the lunar month of Dhu al-Hijjah and is also the third day of the Hajj pilgrimage in Mecca.
For Muslims, Eid al-Adha commemorates the day when Prophet Ibrahim (Abraham) was going to sacrifice his son but was instructed by God to offer an animal instead. Eid al-Adha in Arabic literally means "festival of the sacrifice".
Traditionally, the festival lasts for four days but public holidays vary from country to country.
http://iqna.ir/fa/news/3834390