Date validation dd-mm-yyyy or dd/mm/yyyy

Question

I get dates from a text area in the dd-mm-yyyy or dd/mm/yyyy format (the user is allowed to use - or /) How do I check (using a regex or php) if the date is valid? Is there a regex or php method done this far to validate dates in this format? I tried searching here but could not find anything.

Answer 1

$date = str_replace("/", "-", $incoming);
$d = explode("-"  , $date);

Re-assemble the parts and then run it through checkdate

if( !checkdate($d[1], $d[0], $d[2]) )
echo 'Not a recognised date' ;

http://www.php.net/manual/en/function.checkdate.php

Answer 2

I came up with this little function, it checks you use the format DD(separator)MM(sameseparator)YYYY

With DD, MM and YYYY as integers.

function valid_date($input_date) {
    if(!preg_match('/(?P<d>\d{2})(?P<sep>\D)(?P<m>\d{2})\2(?P<y>\d{4})/',$input_date, $aux_date)) 
        return false; 
    $aux = mktime(0,0,0,$aux_date['m'],$aux_date['d'],$aux_date['y']);
    return $input_date == date('d'.$aux_date['sep'].'m'.$aux_date['sep'].'Y',$aux);
}

(Edited as sugested below)

Answer 3

I highly recommend using the PHP method strtotime() , as it will not only check to see if the format is valid, but if the time specified by the format is correct as well (ie there will never be a February 31st, but a regex might not catch this).

You can check to see if this is valid with if (strtotime($toCheck)) { as it'll return FALSE if it doesn't succeed (http://us2.php.net/strtotime).

EDIT: You'll need to switch the order before you can check if the date is valid with strtotime first like this:

$str = "07-31-1987";
$str = preg_replace('/([^-\/]+)[-\/]([^-\/]+)[-\/]([^-\/]+)/', '$2-$1-$3', $str);
echo date('r', strtotime($str)) . "\n"; // Fri, 31 Jul 1987 00:00:00 -0700

Answer 4

'/^(?=\d)(?:(?:(?:(?:(?:0?[13578]|1[02])(\/|-|\.)31)\1|(?:(?:0?[1,3-9]|1[0-2])(\/|-|\.)(?:29|30)\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})|(?:0?2(\/|-|\.)29\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))|(?:(?:0?[1-9])|(?:1[0-2]))(\/|-|\.)(?:0?[1-9]|1\d|2[0-8])\4(?:(?:1[6-9]|[2-9]\d)?\d{2}))($|\ (?=\d)))?(((0?[1-9]|1[012])(:[0-5]\d){0,2}(\ [AP]M))|([01]\d|2[0-3])(:[0-5]\d){1,2})?$/'

这将做生意。

Answer 5

A very simplistic way would be to have a regular expression that checks for one of the formats, then make sure the input is converted to that first by replacing any characters:

$regexDate = '#\d\d\-\d\d\-\d\d\d\d#' ;

$dateIn = trim($_GET['date']) ;

//replace all / with - since our regex expects those
$dateIn = str_replace('/', '-', $dateIn) ;

if (preg_match($regexDate, $dateIn)) {
    //valid date input
}

Answer 6

I'd use strftime and strptime. At first I'd convert string into "time" than back to string and compare it...

Answer 7

You could use the datetime class, passing the date you want to validate to the constructor. If you have a valid date you'll get back a datetime object. If it's an invalid date the constructor will throw an exception, which you can catch and the handle the error accordingly.

Answer 8

A regular expression alone cannot validate a date because of the different number of days in months - especially for leap years.

/^(\d{1,2})(\/|-)(\d{1,2})\2(\d{2}|\d{4})$/

but above regex solves your problem of allowing - or / based on these format dd-mm-yyyy or dd/mm/yyyy

Here are some examples

//Date d/m/yy and dd/mm/yyyy
//1/1/00 through 31/12/99 and 01/01/1900 through 31/12/2099
//Matches invalid dates such as February 31st
'\b(0?[1-9]|[12][0-9]|3[01])[- /.](0?[1-9]|1[012])[- /.](19|20)?[0-9]{2}\b'

//Date dd/mm/yyyy
//01/01/1900 through 31/12/2099
//Matches invalid dates such as February 31st
'(0[1-9]|[12][0-9]|3[01])[- /.](0[1-9]|1[012])[- /.](19|20)[0-9]{2}'

//Date m/d/y and mm/dd/yyyy
//1/1/99 through 12/31/99 and 01/01/1900 through 12/31/2099
//Matches invalid dates such as February 31st
//Accepts dashes, spaces, forward slashes and dots as date separators
'\b(0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2}\b'

//Date mm/dd/yyyy
//01/01/1900 through 12/31/2099
//Matches invalid dates such as February 31st
'(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)[0-9]{2}'

//Date yy-m-d or yyyy-mm-dd
//00-1-1 through 99-12-31 and 1900-01-01 through 2099-12-31
//Matches invalid dates such as February 31st
'\b(19|20)?[0-9]{2}[- /.](0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])\b'

//Date yyyy-mm-dd
//1900-01-01 through 2099-12-31
//Matches invalid dates such as February 31st
'(19|20)[0-9]{2}[- /.](0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])'

• http://www.roscripts.com/PHP_regular_expressions_examples-136.html