It opened in a mobile-optimized view on my phone, and at the bottom it says, "2 hours ago." It's also listed under August 2011 on the Archive page. But I do agree that most blog posts are generally enhanced by the inclusion of the post date for context.
But if publishers actually follow that advice, they will find that people think the context is virtually invariably "old is bad" and watch their content get written off after a release window measured in days or, recently, hours.
