Hide or Change stripes Date Meta on AMP mode

/* Hide or Change stripes Date Meta on AMP mode */
function remove_stripes_meta_date_on_amp() {
    ?>
    /* to Hide it */
    .amp-wp-posted-on:before {
        display: none;
    }
    /* to Change it to clock icon */
    .amp-wp-posted-on:before {
        content: '\f017';
        font-family: 'FontAwesome';
    }
    <?php
}
add_action( 'amp_post_template_css', 'remove_stripes_meta_date_on_amp' );