Set Posts older than 3 years from current date to draft status

expire_posts

<?php 
/**
 * Set Posts older than 3 years from current date to draft status
 * @link https://gist.github.com/
 * @param string 
 * @return string 
 */
add_action( 'init', 's25_mass_expire' );
function s25_mass_expire(){
	global $wpdb;
	//get the current date as year
	$server_time_yr = date('Y');
	
	//set our cutoff to 3 years back from current date as year
	$cutoffyr = date( 'Y' ,strtotime ( '-3 year' , strtotime($server_time_yr) ) );
	
	//select all published Posts
	$result = $wpdb->get_results("SELECT * FROM wp_posts WHERE post_type = 'post' AND post_status = 'publish'");
	
	//go through each returned Post, if the Post's year is older than the cutoff, set the status of the Post to Draft
	if( !empty($result)) {
		foreach ($result as $a){
			$show_time = get_the_time('Y', $a->ID );
			var_export($show_time);
			if ( $cutoffyr > $show_time){
				$my_post = array();
				$my_post['ID'] = $a->ID;
				$my_post['post_status'] = 'draft';
				wp_update_post( $my_post );
			}
		} // end foreach
	}
}
?>