Yeah and you also have to take into account that people have different time zones as well. It might be evening for some people, and morning for others.
Some of my online friends are 3 hours difference in time zones.
My schedule is definitely hectic. I have a day off today but it's back to work tomorrow, and sometimes I'm working in the evening too.
But as much as I'd like a nice Monday thru Friday 9-5, jobs are scarce and you have to take what you can get. So until I find something better, I have to juggle a schedule that's upside down and sideways.
Sometimes I'll log into the forum at different times of the day when I do get a day off, and see different people come on at different times.
A schedule would have to be used in order to implement the chat I think.