Patrick McKenzie on why having a publication date on your blog entry devalues it.
And yet books always have a publication date.
ETA: as do scientific articles, of course, and the date really matters, not because of being "up to date" but because the date gives some context to whatever it is.
As far as books go:
...Most writing only carries a publication date because that was inserted several years ago into the WordPress template by a designer. The designer likely knows nothing about your company, to say nothing of the instant work. He put in a date because WordPress makes it really easy and because everyone knows that blog posts have dates. He also probably made the decision to make the date front-and-center in the blog post, rather than treating it as minimal-impact metadata and burying it after the main text or putting it in a bots-only header
Another month has passed and here is a new rationality quotes thread. The usual rules are: