add the date

    <footer class="entry-meta">
        <?php
            /* translators: used between list items, there is a space after the comma */
            $categories_list = get_the_category_list( __( ', ', 'twentyeleven' ) );

            /* translators: used between list items, there is a space after the comma */
            $tag_list = get_the_tag_list( '', __( ', ', 'twentyeleven' ) );
            if ( '' != $tag_list ) {
                $utility_text = __( 'This entry was posted on %7$s in %1$s and tagged %2$s by <a href="%6$s">%5$s</a>. Bookmark the <a href="%3$s" title="Permalink to %4$s" rel="bookmark">permalink</a>.', 'twentyeleven' );
            } elseif ( '' != $categories_list ) {
                $utility_text = __( 'This entry was posted on %7$s in %1$s by <a href="%6$s">%5$s</a>. Bookmark the <a href="%3$s" title="Permalink to %4$s" rel="bookmark">permalink</a>.', 'twentyeleven' );
            } else {
                $utility_text = __( 'This entry was posted on %7$s by <a href="%6$s">%5$s</a>. Bookmark the <a href="%3$s" title="Permalink to %4$s" rel="bookmark">permalink</a>.', 'twentyeleven' );
            }

            printf(
                $utility_text,
                $categories_list,
                $tag_list,
                esc_url( get_permalink() ),
                the_title_attribute( 'echo=0' ),
                get_the_author(),
                esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ),
                esc_html( get_the_date() )
            );
        ?>