This has been solved.
add_action('admin_head', 'set_scheduled_today_tag', 99);
function set_scheduled_today_tag() {
global $post;
$args = [
'post_type' => 'wp_events',
'post_status' => 'any',
'numberposts' => -1
];
$posts = get_posts($args);
if ($posts) {
foreach ($posts as $post) {
setup_postdata($post);
$post_date = get_the_date('Y/m/d', get_the_ID());
date_default_timezone_set('America/Chicago');
$current_date = date('Y/m/d');
if ($post_date === $current_date) {
wp_set_object_terms(get_the_ID(), 'today', 'event_tag', true);
}
}
}
wp_reset_postdata();
echo '<style>
.event_tag-checked {
background-color: lightblue!important;
}
.event_tag-today {
background-color: #90EE90!important;
}
</style>';
}