Zadhan (may Allah have mercy on him) said: A man asked Sayyiduna Ali (may Allah be pleased with him) about the ritual bath (ghusl), and he said: If you wish, bathe every day. He said: No, I am not asking about that bath. He said: Bathe on Friday, on the day of Arafah, and on the day of Eid al-Fitr and Eid al-Adha.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6124