Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
Q: Passage: On 28 February 2008, Kibaki and Odinga signed an agreement on the formation of a coalition government in which Odinga would become Kenya's second Prime Minister. Under the deal, the president would appoint cabinet ministers from both PNU and ODM camps depending on each party's strength in Parliament. The agreement stipulated that the cabinet would include a vice-president and two deputy Prime Ministers. After debates, it was passed by Parliament, the coalition would hold until the end of the current Parliament or if either of the parties withdraws from the deal before then. Question: When did Kibaki and Odinga sing an agreement on the formation of government?
A:
28 February 2008