Passage: On 2 March 2011, Merkel announced that Maizière was to take over from Karl-Theodor zu Guttenberg, the federal defence minister who had resigned from office the previous day. On 3 March, he was formally appointed to this post. He held the defence ministry portfolio until 17 December 2013.

Question: until when did Merkel hold his defence ministry portfolio
17 December 2013