A well balanced game can take up to 45+ minutes to complete in a 5v5 setting. Making each team v team setup taking 4 hours if only 4 matches are played. Kind of like pool play which is what I am going to guess will be Saturdays festivities.
Then the actual tournament play which is another 4 total games which could take up 16 hours is all matches take an hour and they broadcast the two lower matches instead of just the semi-finals and finals. They could use all 3 days but didn't. So there will be lots of hours of play to watch!