$date="2012-09-12"; if (preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)) { return true; } else { return false; }
const formatYmd = date => date.toISOString().slice(0, 10); formatYmd(new Date());