Source From http://www.problogger.net/archives/2008/09/15/when-to-publish-blog-posts-timing-considerations/

Weekends

The day of the week that you publish can have a big impact upon how many people read it. While RSS feeds might mean some of your readers will read posts published when they are away from their computer I find that posts that go live on weekends tend to get a lot less traction than weekday posts. The exception to this is of course for blogs with a topic that is weekend specific (sports or certain TV shows for example). The other advantage of weekends is that I find it can be easier to crack the front page on sites like Digg as there seems to be less competition.

Mid Week

If I have a very important post that I want to get as much attention as possible I generally will publish it on a Tuesday or Wednesday morning (my time). This gives a few days after the post is written for it to be found, linked to, bookmarked etc before the weekend arrives (and momentum stops) - but means that those in catchup mode after the weekend have a little more time to digest the post. [Read more]