A tournament of claimants to the chess crown took place in London from March 14 to April 2, 2013. Magnus Carlsen, Vladimir Kramnik, Boris Gelfand, Levon Aronian, Teimour Radjabov, Alexander Grischuk, Vassily Ivanchuk, and Peter Svidler took part.
It's a double round-robin tournament with four rest days. The players were given 120 minutes for the first 40 turns, then 60 minutes for the next 20 turns and 15 minutes with an added 30 seconds per turn to the end of the match.
Details are available on the official website of the Candidates Tournament.