Analysis of information sources in references of the Wikipedia article "List of emperors of the Han dynasty" in English language version.
On 11 December [...] Cao Cao's son and successor Cao Pi received the abdication of the last emperor of Han. [...] Some authorities give the date of abdication as 25 November [...] This is the date upon which Emperor Xian issued an edict calling upon Cao Pi to take the throne, but the ceremonial transfer of sovereignty was carried out two weeks later