I noticed that C.SE, Meta.C.SE and chat(The Upper Room etc.) are so quiet around the weekends. What might be the reason for less activities during this time? I guess most of us are busy going to church or enjoying the weekends (not going church at all). Any thoughts on this?
Because of its roots in and continued close ties with the rest of the SE network, the user base of this site is still heavily weighted towards folks whose work brings them online looking for answers. Many of us are programmers, IT professionals or in related fields that had us using SE sites before Christianity.SE became a site. We are on the computer and online during the work week* and our participation in anything online is focused around those times. Asking and answering questions is not such a high priority that it trumps the rest of life and any time we have to escape the glow of the LCD, we do.
This combines with the overall habits of Christians to use our time away from work to concentrate on other purposes as well as our observance of the Lords Day as a day of rest to keep our attention diverted away from SE more often on the weekends than during the week.
* For some, like myself, the work week is the long and irregular hours of a freelancer, but the principle still applies.