Wordpress wp_query date range date_from date_to filter.

wp_query_date_range.php

<?php

// https://gist.github.com/krava/6322195
// Wordpress wp_query date range date_from date_to filter.
add_filter('posts_where', 'wapp_filter_posts_where');
function wapp_filter_posts_where($where) {
	global $wp_query;
	if (isset($wp_query->query['date_from']) && isset($wp_query->query['date_to'])) {
		$date_from = $wp_query->query['date_from'];
		$date_to = $wp_query->query['date_to'];
		$r = '/^\d{4}-\d{2}-\d{2}$/';
		if (!(preg_match($r, $date_from) && preg_match($r, $date_to)))
			die('invalid date format for date_from and date_to');
		$where .= " AND post_date BETWEEN STR_TO_DATE('$date_from 00:00:00', '%Y-%m-%d %H:%i:%s') AND STR_TO_DATE('$date_to 23:59:59', '%Y-%m-%d %H:%i:%s')";
	}
	return $where;
}