Geoffrey Chaucer, John Steinbeck, Jack London, John Grisham, George R R Martin and J K Rowling all have something in common. So do Tom Cruise, John Travolta, Ben Affleck, and Robert Pattinson to name a few.
What they have in common is they have all created or been seen in stories that are classics and a classic is something that is timeless.
You will want your blog to be around for a while as you will want readers to come in, say 5 years-time. To do that every time they visit your blog the information has to be relevant.
If it is relevant to your key audience, they will keep coming back.
But there is a difference between writing stuff that is timeless versus stuff that is opportunistic. i.e. a blog promoting a flash sale is a one-off blog – unless your audience is opportunity seekers in which case each blog may be about a specific promotion.
But if your blog is focused on a specific niche, problem, product group, or service then you need to write about a key principle, angle, or story.
This not only means you don't have to keep updating your content every 5 minutes - which will save you time – but it also helps with other people who you may allow to use your content on their websites.
They are sure not going to update your content for you.
Some topics however, will always be timeless. Find those, write on them.