Succeeding the EOS 5D Mark II, it was announced on 2 March 2012, the 25th anniversary of the announcement of the first camera in the EOS line, the EOS 650, and was also Canon's 75th anniversary. The Mark III went on sale later in March with a retail price of $3,499 in the US, 2999 in the UK, and 3569 in the Eurozone.

Based on this passage, when did the canon 5d mark iii come out? Let's think fast. Stream of consciousness:
The relevant sentence in the passage is: Succeeding the EOS 5D Mark II, it was announced on 2 March 2012, the 25th anniversary of the announcement of the first camera in the EOS line, the EOS 650, and was also Canon's 75th anniversary. So the final answer is 2 March 2012.