Timing is not everything.

This article today brought up an interesting question regarding how the school days are being used. I'm not sure on which side of the debate I stand. On the one hand, longer school days, and/or more of them, would help give students more time to grasp the material, and more time for teachers to elicit more information. On the other hand, how much of this time would be used efficiently? Would this extra time simply give bad teachers more time to waste? Obviously, extending the school day cannot be seen as a solution in and of itself, but I do see the importance of the debate, and why it is not easily solved.