It’s may be just a matter of specifying the post type in the Query.
It sounds like you know this, but remember… the below code naturally has values that need to be replaced:
a) ‘my_custom_post_type’ = the ‘slug’ of your post type (3 places… plus the function name twice if desired)
b) ‘date’ = the ‘name’ of your ACF Date field (1 place)
<?php
function mycustomposttype_pre_get_posts() {
if ( is_admin() ) { return $query; }
if ( is_post_type_archive( 'my_custom_post_type' ) && !empty( $query->query['post_type'] == 'my_custom_post_type' ) {
$query->set( 'post_type', 'my_custom_post_type' );
$query->set( 'meta_key', 'date' );
$query->set( 'orderby', 'meta_value_num' );
$query->set( 'order', 'DESC' );
}
return $query;
}
add_action('pre_get_posts','mycustomposttype_pre_get_posts');
?>
You may need to adjust ‘orderby’. I got ‘num’ from the ACF docs about querying date fields.
