Sayyiduna Mu'awiyah (may Allah be pleased with him) asked Sayyiduna Zayd bin Arqam (may Allah be pleased with him): Were you present with the Prophet (peace and blessings be upon him) when two Eids coincided on one day? He said: Yes. Sayyiduna Mu'awiyah (may Allah be pleased with him) asked: Then what did he (peace and blessings be upon him) do? He said: He (peace and blessings be upon him) led the Eid prayer, then gave a concession regarding the Jumu'ah and said: "Whoever wishes to pray, let him pray."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6286