On my blog when I choose I want to see 8 days in the main page, it shows posts from today (January 29, 2009) to December 22, 2008.or
Is this "8" days for you?
Why can't I ever predict how many posts I'll see in 5 days?and what we have here are bloggers who don't understand what "Show 7 Days" really means.
If we select "Show 7 Posts on the main page", we get a maximum of 7 posts displayed in main page view. Many bloggers figure that "Show 7 Days on the main page", similarly, means show all of the posts in the most recent 7 days span of time. Blogger, however, doesn't see it that way.
If you set "Show" to "7 days", you could get anywhere from 7, to any number, of posts. If you posted once / day for 6 days, and 5 times on the 7th day, you'll end up with 11 posts. If that 7 days is from 6 days in a consecutive stretch, plus one day a month ago (with no posts made during a month), you'll end up with posts from a month ago. "7 days" = 7 days of posts, not all posts from the last week, consistently.
Note that if your blog uses a dynamic template, none of this matters - blogs with dynamic templates do not archive, and are not subject to auto pagination or main page sizing.