WordPress Custom RSS Feed with Offset

feed-offset

<?php
/**
 * RSS2 Feed Template for displaying RSS2 Posts feed.
 * Adds an offset of "1" to display all but most recent
 * Full details at: https://wordimpress.com/anatomy-advanced-wordpress-blog-notification-email
 * @package WordPress
 */

header('Content-Type: ' . feed_content_type('rss-http') . '; charset=' . get_option('blog_charset'), true);
$more = 1;

echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>';

/**
 * Fires between the <xml> and <rss> tags in a feed.
 *
 * @since 4.0.0
 *
 * @param string $context Type of feed. Possible values include 'rss2', 'rss2-comments',
 *                        'rdf', 'atom', and 'atom-comments'.
 */
do_action( 'rss_tag_pre', 'rss2' );
?>
<rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
	<?php
	/**
	 * Fires at the end of the RSS root to add namespaces.
	 *
	 * @since 2.0.0
	 */
	do_action( 'rss2_ns' );
	?>
>

<channel>
	<title><?php bloginfo_rss('name'); wp_title_rss(); ?></title>
	<atom:link href="<?php self_link(); ?>" rel="self" type="application/rss+xml" />
	<link><?php bloginfo_rss('url') ?></link>
	<description><?php bloginfo_rss("description") ?></description>
	<lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
	<language><?php bloginfo_rss( 'language' ); ?></language>
	<?php
	$duration = 'hourly';
	/**
	 * Filter how often to update the RSS feed.
	 *
	 * @since 2.1.0
	 *
	 * @param string $duration The update period.
	 *                         Default 'hourly'. Accepts 'hourly', 'daily', 'weekly', 'monthly', 'yearly'.
	 */
	?>
	<sy:updatePeriod><?php echo apply_filters( 'rss_update_period', $duration ); ?></sy:updatePeriod>
	<?php
	$frequency = '1';
	/**
	 * Filter the RSS update frequency.
	 *
	 * @since 2.1.0
	 *
	 * @param string $frequency An integer passed as a string representing the frequency
	 *                          of RSS updates within the update period. Default '1'.
	 */
	?>
	<sy:updateFrequency><?php echo apply_filters( 'rss_update_frequency', $frequency ); ?></sy:updateFrequency>
	<?php
	/**
	 * Fires at the end of the RSS2 Feed Header.
	 *
	 * @since 2.0.0
	 */
	do_action( 'rss2_head');
	query_posts('offset=1');
	while( have_posts()) : the_post();
	?>
	<item>
		<title><?php the_title_rss() ?></title>
		<link><?php the_permalink_rss() ?></link>
		<comments><?php comments_link_feed(); ?></comments>
		<pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_post_time('Y-m-d H:i:s', true), false); ?></pubDate>
		<dc:creator><![CDATA[<?php the_author() ?>]]></dc:creator>
		<?php the_category_rss('rss2') ?>

		<guid isPermaLink="false"><?php the_guid(); ?></guid>
		<description><![CDATA[<?php strip_tags(the_excerpt()); ?>]]></description>
		<content:encoded><![CDATA[<?php strip_tags(the_excerpt()); ?>]]></content:encoded>
		<?php rss_enclosure(); ?>
			<?php
				/**
				 * Fires at the end of each RSS2 feed item.
				 *
				 * @since 2.0.0
				 */
				do_action( 'rss2_item' );
			?>
	</item>
	<?php endwhile; ?>
</channel>
</rss>

EDIT: Someone recently contacted me wanting to see my version of this code. So I've created a Gist at https://gist.github.com/seezee/606b015926643d861918407a31f04756.

Line 10 overrides a Wordpress global. Not only is that bad, but I'm also not even sure if it's necessary. Your code seems to work fine without it.

You should also consider using WP_Query instead of query_posts (line 79). Hit me up if you want to see my code for implementing this.