Wordpress: Get posts between dates based on specific post meta field

get_posts_between.php

<?php

/**
 * Get posts in range date by a specific custom field(post meta)
 * But, the date needs to be in the format YYYYMMDD
 * 
 * @param  string $start start date
 * @param  string $end   end date
 * @param  string $field specific custom field
 * @param  string $ctype 
 * @return array  of posts
 */
function get_posts_between($start, $end, $field, $ctype = 'post')
{
    $args       = ['post_type' => $ctype, 
        'meta_query' => [
                [
                    'key'     => $field,
                    'value'   => [$start, $end],
                    'compare' => 'BETWEEN',
                    'type'    => 'DATE'
                ]
            ]
    ];
    $query      =  new WP_Query($args);
    return $query->get_posts();
}