Customized WordPress RSS Feed. REPLACE the value of the variable $date before employing!

feed-offset-template.php

<?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 Your Package Name
 */

/**
 * TO USE:
 * 1. Update the package name
 * 2. Update the value for the $date variable
 * 3. Save changes and place this file in the your theme's root folder
 * 4. Create a new page; this will be the custom feed page
 * 5. On the new page, go to Page Attribute > Template & use the dropdown to select
 *    the Feed Offset template (this template)
 * 6. Publish the new page
 */

// Security.
if ( ! defined( 'ABSPATH' ) ) {
	die( 'Sorry, you are not allowed to access this page directly.' );
}

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

$arr = array(); // For wp_kses.
$date = "PUT YOUR COPYRIGHT START DATE HERE";

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

/**
 * 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>
		<language>en-us</language>
		<title>
			<?php
			bloginfo_rss( 'name' );
			echo ' ';
			wp_title_rss();
			?>
		</title>
		<copyright>Copyright ©<?php echo $date; ?> — <?php echo date('Y'); ?> <?php bloginfo( 'name' ); ?>. All rights reserved.</copyright>
		<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 wp_kses( mysql2date( 'D, d M Y H:i:s +0000', get_lastpostmodified( 'GMT' ), false ), $arr ); ?></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 wp_kses( apply_filters( 'rss_update_period', $duration ), $arr ); ?></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 wp_kses( apply_filters( 'rss_update_frequency', $frequency ), $arr ); ?></sy:updateFrequency>
		<?php
		/**
		 * Fires at the end of the RSS2 Feed Header.
		 *
		 * @since 2.0.0
		 */

		do_action( 'rss2_head' );
		$args = array(
			'offset' => 1,
		);

		// Custom query.
		$query = new WP_Query( $args );

		// Check that we have query results.
		if ( $query->have_posts() ) {

			// Start looping over the query results.
			while ( $query->have_posts() ) :
				$query->the_post();
				?>
		<item>
			<title><?php the_title_rss(); ?></title>
			<link><?php the_permalink_rss(); ?></link>
			<comments><?php comments_link_feed(); ?></comments>
			<pubDate><?php echo wp_kses( mysql2date( 'D, d M Y H:i:s +0000', get_post_time( 'Y-m-d H:i:s', true ), false ), $arr ); ?></pubDate>
			<dc:creator>
				<![CDATA[<?php the_author(); ?>]]>
			</dc:creator>
				<?php the_category_rss( 'rss2' ); ?>

			<guid isPermaLink="false"><?php the_guid(); ?></guid>
			<description>
				<![CDATA[<?php wp_strip_all_tags( the_excerpt() ); ?>]]>
			</description>
			<content:encoded>
				<![CDATA[<?php wp_strip_all_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;
		}
		// Restore original post data.
		wp_reset_postdata();
		?>
	</channel>
</rss>
	<?php