WordPress at a glance
function is not described

_close_comments_for_old_post() WP 2.7.0

Close comments on an old post. Hooked to comments_open and pings_open.

Hooks in function
Return

true/false. $open

Usage

_close_comments_for_old_post( $open, $post_id );
$open(true/false) (required)
Comments open or closed
$post_id(int) (required)
Post ID

Code of close comments for old post: wp-includes/comment.php WP 5.2.2

<?php
function _close_comments_for_old_post( $open, $post_id ) {
	if ( ! $open ) {
		return $open;
	}

	if ( ! get_option( 'close_comments_for_old_posts' ) ) {
		return $open;
	}

	$days_old = (int) get_option( 'close_comments_days_old' );
	if ( ! $days_old ) {
		return $open;
	}

	$post = get_post( $post_id );

	/** This filter is documented in wp-includes/comment.php */
	$post_types = apply_filters( 'close_comments_for_post_types', array( 'post' ) );
	if ( ! in_array( $post->post_type, $post_types ) ) {
		return $open;
	}

	// Undated drafts should not show up as comments closed.
	if ( '0000-00-00 00:00:00' === $post->post_date_gmt ) {
		return $open;
	}

	if ( time() - strtotime( $post->post_date_gmt ) > ( $days_old * DAY_IN_SECONDS ) ) {
		return false;
	}

	return $open;
}