Correctly determine if date string is a valid date in that format

Question

I\'m receiving a date string from an API, and it is formatted as yyyy-mm-dd.

I am currently using a regex to validate the string format, which works ok,

Answer 1

You can also Parse the date for month date and year and then you can use the PHP function checkdate() which you can read about here: http://php.net/manual/en/function.checkdate.php

You can also try this one:

$date="2013-13-01";

if (preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date))
    {
        echo 'Date is valid';
    }else{
        echo 'Date is invalid';
    }