A scheduled site-wide banner in WooCommerce / WordPress

scheduled-site-wide-banner-wordpress-woocommerce.php

<?php // For implementation instructions see: https://aceplugins.com/how-to-add-a-code-snippet/

/**
 * Basic site-wide banner.
 */
function ace_custom_site_banner() {
	$from_time = new DateTime( '2019-04-21 00:00' );
	$to_time = new DateTime( '2019-04-22 23:59' );

	if ( new DateTime() > $from_time && new DateTime() < $to_time ) {
		?><div class="site-banner">
			<span>
				<strong style="">Sale!</strong> Get up to 50% off, sale ending this friday.
			</span>
		</div><?php
	}
}
add_action( 'wp_footer', 'ace_custom_site_banner' );