Delete/reset custom field value weekly

I’m developing a theme and is looking for a direction to how could I delete/reset custom field value to zero on weekly basis (On sunday).

I’ve tried the following code for post_views_count custom field but it’s not working. Any idea?

function hits_reset_zero_schedule() {
  if ( ! wp_next_scheduled( 'hits_reset_to_zero') )
    wp_schedule_event( time(), 'weekly', 'hits_reset_zero' );
}
add_action( 'wp', 'hits_reset_zero_schedule' );

function hits_reset_zero_func() {
  delete_post_meta( $post_id, 'post_views_count', true );
}
add_action( 'hits_reset_zero', 'hits_reset_zero_func' );