Mondays, on Cartoon Network
Cartoon Network Wiki

I guess this started sometime in 2010. Some shows I've watched a bit of in the block include Adventure Time, The Amazing World of Gumball, MAD, and Regular Show. However, I often had better things to watch on broadcast networks, so I didn't get a chance to see much of this block, and then I lost access to Cartoon Network in June of 2011, so I've been missing these series entirely, since then.