markhowellsmead

<?php

/**
 * Complex WordPress meta query by start and end date (custom meta fields)
 * Intended for use on the `pre_get_posts` hook.
 * Caution; this makes the query very slow - several seconds - so should be 
 * implemented with some form of caching.
 *
 * mark@sayhello.ch 22.10.2019, based on code from 201 onwards
 */