Anas (ra), a companion of prophet Muhammad (peace be upon him) reported that when the Prophet Muhammad (PBUH) migrated from Makkah to Madinah, the people of Madinah used to have two festivals. On those two days they had carnivals and festivity. Prophet Muhammad (PBUH) asked the Ansaar (the Muslims of Madinah) about it. They replied that before Islam they used to have carnivals on those two joyous days. The Prophet Muhammad (PBUH) told them: 'Instead of those two days, Allah has appointed two other days which are better, the days of Eid-al-Fitr and Eid-al-Adha.' (Hadith)