this is only an example, it will probably need to be adjusted based on your post types/fields.
function update_active_based_on_date() {
// set the date
$date = date('YMD');
// query to get all posts with date < today
$args = array(
'post_type' => array(/* list of your post types here */),
'posts_per_page' => -1,
'meta_query = array(
array(
'key' => 'fl_date',
'value' => $date,
'compare' => '<'
)
) // end meta_query
); // end $args
$query = new WP_Query($args);
// if posts are returned, loop over them and set active flag to false
if ($query->have_posts()) {
global $post;
while ($query->have_posts()) {
$query->the_post();
update_field('active_field_name', 0, $post->ID);
} // end while have_posts
wp_reset_postdata();
} // end if have_posts
} // end function
