I'm usually on the matchmaking in the evenings during the week (USA, CST) and the times I usually see people on matchmaking is around 10PM CST. As I understand it a lot more people are on matchmaking during the morning and afternoon (USA, CST), I usually try to be on between 7pm and 11pm (USA, CST). Weekends I dont have as much experience with as until recently I haven't had the time to play much at all then.