They could schedule a chat for that time, but you'd probably be in the chat room by yourself anyway because everyone's working/in class/etc. Also, there's a Sunday afternoon chat for those who cannot make it to the weekday evening scheduled chats. Sometimes even during scheduled evening chats there's only one or two people in the room; it's not mandatory for anyone to be there and some nights are really really busy and some nights are not.
Haha I'm on the forums when I'm at work when I have down time. Forum posting is easier for me to pick up a conversation in case I get really busy instead of trying to catch up after having to leave a chat room.