Regex ngày tháng dd/mm/yyyy

const re = /^(0[1-9]|[12]\d|3[01])\/(0[1-9]|1[0-2])\/\d{4}$/m;
const matches = str.match(re);

preg_match_all('~^(0[1-9]|[12]\d|3[01])\/(0[1-9]|1[0-2])\/\d{4}$~m', $str, $matches);
print_r($matches);

import re
pattern = re.compile(r"^(0[1-9]|[12]\d|3[01])\/(0[1-9]|1[0-2])\/\d{4}$", re.MULTILINE)
matches = pattern.findall(text)

re := regexp.MustCompile(`^(0[1-9]|[12]\d|3[01])\/(0[1-9]|1[0-2])\/\d{4}$`)
matches := re.FindAllString(str, -1)