Line error shown with WP_debug

This is the line in question: https://github.com/Automattic/amp-wp/blob/0.7.2/includes/amp-helper-functions.php#L659

Please try to find out what get_the_date( 'U', $post->ID ) is returning.

The issue is also happening down in the post further:

Warning: A non-numeric value encountered in /www/wp-includes/formatting.php on line 3237 49 years ago

So I believe the issue is that your underlying post or page has an empty post_date, or you may have a get_the_date a filter that is causing the problem.

Thanks found this code snippet

function et_last_modified_date_blog( $the_date ) {
    if ( 'post' === get_post_type() ) {
        $the_time = get_post_time( 'His' );
        $the_modified = get_post_modified_time( 'His' );
 
        $last_modified =  sprintf( __( 'Last updated %s', 'Divi' ), esc_html( get_post_modified_time( 'M j, Y' ) ) );

        $published =  sprintf( __( 'Published on %s', 'Divi' ), esc_html( get_post_time( 'M j, Y' ) ) );
 
        $date = $the_modified !== $the_time ? $last_modified . ' | ' .  $published : $published;
 
        return $date;

    }
}

add_action( 'get_the_date', 'et_last_modified_date_blog' );
add_action( 'get_the_time', 'et_last_modified_date_blog' );

Is there a condition I can use to have this turn off for AMP?

Your snippet should look like this instead: https://gist.github.com/westonruter/428d2bc4c643873d0f476b03fb52f526

It is important to always return a value from a filter and in the case of filtering the date, never modify it if the Unix timestamp (the integer of seconds since 1970) is requested.

Thanks for helping with this, I also found the templates folder in your plugin. Which is perfect since I wanted to change what the text says as well ??