1、时间格式 2021-10-10 09:50:32

$string = '2020-10-10 12:00:05';
$pattern = ' /^[1-9]\d{3}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])\s+(20|21|22|23|[0-1]\d):[0-5]\d:[0-5]\d$/';
if (!preg_match($pattern, $string)) {
    print_r(2);die;
} else {
    print_r(1);die;
}