Hi!
Sure! I think the timestamp needs to be adjusted to the beginning of the current day (from 00:00 AM), so maybe changing the code to this:
add_filter("asp_query_args", "asp_query_args_apply_date", 10, 2);
function asp_query_args_apply_date($args, $search_id) {
$args['post_meta_filter'][] = array(
'key' => 'evcal_srow',
'value' => strtotime("today", time()),
'operator' => '>=',
'allow_missing' => false
);
return $args;
}