What is the ruling on sports clubs holding celebrations for the 25th or 50th anniversary (Silver or Golden Jubilee)?

Celebrating the fiftieth anniversary of an institution's establishment is an alien tradition adopted from disbelievers, specifically from the Jews who celebrate what they call the "Silver Jubilee" every 49 years, with the fiftieth year being the festive year. In this year, lands are returned, debtors and prisoners of disputes are freed, and properties are restored to their owners. It has been authentically narrated from the Prophet, peace and blessings be upon him, that he said: "Whoever imitates a people is one of them." Furthermore, taking this occasion as an Eid is unlawful, for Muslims have no Eids other than those prescribed by Islamic law.