Is it reprehensible or religiously objectionable to conduct a marriage contract between the two Eids?

There is no harm in concluding the marriage contract and consummating the marriage between the two Eid festivals (Eid al-Fitr and Eid al-Adha), and it is not disliked. Indeed, the Prophet, peace and blessings be upon him, married and consummated his marriage with Aisha, may Allah be pleased with her, in Shawwal. This refutes what the people of Jahiliyyah (pre-Islamic era) used to believe regarding the dislike of this due to their pessimism associated with the name of Shawwal.