In my freelance marketing content-writing life (aka day job) I often do online research on a wide range of topics, from industrial applications of augmented reality to work visa rule changes in Australia. Many of these topics are time-sensitive, that is, things are changing quickly, and it is important for me to know what the current state of play is.
Which is why it drives me batty when people don't put the date of the blog post or article clearly, right at the top. I actually had one client redo their blog so that none of the posts have dates on them.
I think this is to make them seem somehow evergreen. That's cheesy, like tricking people into clicking on something, but it also misses a category point.
Understanding the point of these things
There certainly are evergreen pieces, which explain the basics of something, provide a guide to a complex area, or are funny (though even those should have dates on them). But there are also up-to-the-minute pieces that derive their interest from being fresh. And, like fish, they go bad quickly.
So I want to know, how recent is this information, particularly when it contains an interesting recommendation or course of action. Does that recommendation refer to the current state, or some past state? Is the information still valid? Don't make the reader sniff the fish.
Certainly there are ways of digging out the information, though they don't always work. In Firefox, right clicking on the post and selecting View Page Info might show you the published_time and modified_time metatags (don't get excited about the Modified above the tag list—that's right now, the modification you made by looking at the page). If that doesn't work, sometimes a dig into View Page Source might show you something, but that's pretty tormenting.
Make no law
I'm not serious about the law thing, just so you know. For a long time there was a two-panel comic strip called There Oughta Be A Law that got at this weird urge to petition the legislature to pass more laws preventing things that annoy us. My town of Cambridge, for example, has a complex law regulating when you can use leaf blowers, because someone was annoyed by them.
No, think if this as more of a plea. Please, put the date on the post! Not just for researchers, but for everyone. The older the internet gets, the more obsolete material there will be on it. Don't make it harder for everyone.
If you still blog, do you date your posts?
How about leftovers in the refrigerator? I fall down on that one, I will admit.