new check of wordpress

gistfile1.php

/*-----------------------------------------------------------------------------------*/
/* Get newest post day of each category
/*-----------------------------------------------------------------------------------*/
if ( !function_exists( 'wallpress_is_new_post' ) ) :
function wallpress_is_new_post( $post_id ) {
	//Get newest point of time of each category, must be newest and lessthan 3 days
	$categories = get_the_category( $post_id );
	foreach ( $categories as $category ) {
		$date = wallpress_newest_post_category( $category->cat_ID );
		$post_date = get_the_time( 'Y-m-d', $post_id );
		//if date of post equal to date of recent post and date difference with current date less than 3 day
		if ( ( strtotime( $post_date ) - strtotime( $date ) >= 0 ) && ( ( strtotime( $post_date ) - time() )/( 60*60*24 ) > -3 ) ) {
			return true;
		}
	}
	return false;
}
endif;

/*-----------------------------------------------------------------------------------*/
/* Get newest post in a categry
/*-----------------------------------------------------------------------------------*/
if ( !function_exists( 'wallpress_newest_post_category' ) ) :
function wallpress_newest_post_category( $category_id ) {
	$args = array(
		'numberposts' => 1,
		'offset' => 0,
		'category' => $category_id,
		'post_status' => 'publish'
	);
	$posts = get_posts( $args );
	$date = get_the_time( 'Y-m-d', $posts[0]->ID );
	return $date;
}
endif;