Many MMOs have maintenance during the regular week. EVE Online's server goes down each morning between 6 and 7 AM Eastern. As I type this the World of Warcraft servers are offline, and there are rather a lot of people deciding what to do with the remainder of their day. Some are headed to school or work and the servers should be back up before they're home, hopefully. Others are planning a long day of spending quality time with their chores.