Eid al-Adha (the Feast of the Sacrifice, the Greater Eid) is one of the two most significant festivals in Islam. It is begins on the tenth day of the Islamic month of Dhu al-Hijjah and lasts for three days. Eid al-Adha is an official public holidays in many countries.
International Chocolate Day is an unofficial holiday, dedicated to the sweetest and tastiest dainty in the world – chocolate. This day is celebrated on September 13, since it's birthday of Milton S. Hershey, an American confectioner and founder of worldwide known company The Hershey Chocolate Company.