There are hundreds of events like this – National Tea Day, British Sandwich Week, International Lefthanders Day etc.
They can be useful to journalists by providing a news hook to a story. Magazines and newspapers are actively looking for stories for some of the bigger events, such as Breast Cancer Awareness Month and Veganuary.
The ones you need to be more careful with are those that are invented by an industry or company for the sole reason of promoting their products.
While you can sometimes use them to place stories, many commissioning editors won’t take them seriously enough as news hooks.
Also, bear in mind that commissioning editors will be approached directly by PRs promoting these days, reducing your chances of selling a feature.
So, if you have an idea and it happens to coincide with one of these special days, by all means mention it. But for the smaller events, I would suggest you don’t wait until the “day” to pitch it.
There are many lists of the ‘World’ or ‘National’ days and weeks, but here are a few to get you started: