WordPress custom post types can be very useful for storing all sorts of different types of data in WordPress — and I should really write a post about that some time. But the date a post was published, i.e. its post_date, isn’t important for many custom post types. So why have a drop-down list of dates to filter your custom posts types by if you don’t need it?

For a recent job, I created a custom post type for Stores, with a couple of useful custom taxonomies called Brand and Product Type that I can filter by. I have no need to filter by the post date, it is of no use to my client. Some might say it’s useful for finding the most recently added store — but the client actually searches by name, brands sold, and products sold, not by when they added the store.

So here’s what I get normally:

And here’s what I want:

Removing that little drop-down box was very easy. All I needed to do was replace the list of post dates with an empty list, and WordPress dropped the drop-down. And all it took was this little filter:

add_filter('months_dropdown_results', '__return_empty_array');

OK, yes, I needed to ensure that was only called for my custom post type, but I already do that by separating its admin functionality into its own class which I load based on the value of $typenow.

Note: WordPress has a nice little collection of handy functions that are ready made for filter hooks, including the one I use above. When all you need is a function that returns one of these simple values, no matter what, then it’s best to use one of these — it means one less function to define in your own code, and thus one less thing to document and test! Here’s the full set:

• __return_false()
• __return_true()
• __return_zero()
• __return_null()
• __return_empty_array()
• __return_empty_string()

So for simple jobs like this one, job can be done with a single well-placed filter hook.