/* 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' );