If you are a regular reader of this blog, you may recognise that I tend to blog once a day, and that I normally do so just before midnight (Canberra time). It used to be that if I started a post before midnight, it would show up as have been written on that day (even if I finished it after midnight). However I recently switched to the new Blogger editor, and it now takes the post date from when I post the entry, not from when I start it. This explains why I have no posts on a Tuesday (for example), and 2 on a Wednesday.
(Of course this may interest no one but me, but it irks me enough to give an explanation!)