Sayyiduna Anas (may Allah be pleased with him) narrates: A man said: O Messenger of Allah! In the Jahiliyyah we used to sacrifice animals as 'atirah; what do you now command us? The Prophet (peace and blessings be upon him) said: Slaughter in any month, whichever month it may be, obey Allah Almighty, and feed (others).
Al-Tabarani recorded it in al-Mu'jam al-Awsat as a narration of Mu'awiyah bin Wahib from his paternal uncle Unays, and I do not know either of them.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأضاحي / 6007