php 根据出生日期生成年龄

<?php$birthday = '1985-02-01';$age = date('Y', time()) - date('Y', strtotime($birthday)) - 1;if (date('m', time()) == date('m', strtotime($birthday))){if (date('d', time()) > date('d', strtotime($birthday))){$age++;}}elseif (date('m', time()) > date('m', strtotime($birthday))){$age++;}echo $age;?>mysql 当前时间-n年计算select date_add(curdate(), interval -1 year);