PHP Regex to check date is in YYYY-MM-DD format

I'm trying to check that dates entered by end users are in the YYYY-MM-DD. Regex has never been my strong point, I keep getting a false return value for the preg_match() I have setup.

So I'm assuming I have made a mess of the regex, detailed below.

$date="2012-09-12";


if (preg_match("^[0-9]{4}-[0-1][0-9]-[0-3][0-9]$",$date))
{
return true;
}else{
return false;
}

Any thoughts?

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  • array_pad is used (with a default value that will cause checkdate to fail) to make sure that enough elements are returned so that if the input is "1-2" list() will not emit a notice
    • 小开
    最佳答案

    I had a similar issue with Datagrip and none of these solutions worked.

    Try this.

    $date="2012-09-12";


if (preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)) {
return true;
} else {
return false;
}
    小开

    Once I restarted the Datagrip Client it was no longer an issue and I could drop tables again.

    You can make it this way:

    if (preg_match("/\d{4}\-\d{2}-\d{2}/", $date)) {
echo 'true';
} else {
echo 'false';
}
    s one:

    $date = DateTime::createFromFormat('Y-m-d', $date);
if ($date) {
echo $date -> format('Y-m-d');
}

    but you'd better use this one:

    $date = DateTime::createFromFormat('Y-m-d', $date);
if ($date) {
echo $date -> format('Y-m-d');
}

    in this case you'll get an object which is muck easier to use than just strings.

    小开
    lter unlocked immediately.

    小开

    preg_match needs a / or another char as delimiter.

    preg_match("/^[0-9]{4}-[0-1][0-9]-[0-3][0-9]$/",$date)

    you also should check for validity of that date so you wouldn't end up with something like 9999-19-38

    bool checkdate ( int $month , int $day , int $year )
    小开

    If you want to match that type of date, use:

    preg_match("~^\d{4}-\d{2}-\d{2}$~", $date)
    小开

    This should tell you if the format is valid and if the input date is valid.

        $datein = '2012-11-0';


if(preg_match('/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/', $datein)){
echo 'good';
}else{
echo 'no good';
}
    小开

    It all depends on how strict you want this function to be. For instance, if you don't want to allow months above 12 and days above 31 (not depending on the month, that would require writing date-logic), it could become pretty complicated:

    function checkDate($date)
{
$regex = '/^' .
'(' .


// Allows years 0000-9999
'(?:[0-9]{4})' .
'\-' .


// Allows 01-12
'(?:' .
'(?:01)|(?:02)|(?:03)|(?:04)|(?:05)|(?:06)|(?:07)|(?:08)|(?:09)|(?:10)|' .
'(?:11)|(?:12)' .
')' .
'\-' .


// Allows 01-31
'(?:' .
'(?:01)|(?:02)|(?:03)|(?:04)|(?:05)|(?:06)|(?:07)|(?:08)|(?:09)|(?:10)|' .
'(?:11)|(?:12)|(?:13)|(?:14)|(?:15)|(?:16)|(?:17)|(?:18)|(?:19)|(?:20)|' .
'(?:21)|(?:22)|(?:23)|(?:24)|(?:25)|(?:26)|(?:27)|(?:28)|(?:29)|(?:30)|' .
'(?:31)' .
')' .


'$/';


if ( preg_match($regex, $date) ) {
return true;
}


return false;
}


$result = checkDate('2012-09-12');

    I need to control the access to views based on users privilege levels (there are no roles, only privilege levels for CRUD operation levels assigned to users) in my MVC 4 application.

    Personally I'd just go for: /^([0-9]{4}\-([0-9]{2}\-[0-9]{2})$/

    小开

    To work with dates in php you should follow the php standard so the given regex will assure that you have valid date that can operate with PHP.

        preg_match("/^([0-9]{4})-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)
    小开

    As an example; below the AuthorizeUser will be my custom attribute and I need to use it like this:

    [AuthorizeUser(AccessLevels="Read Invoice, Update Invoice")]
public ActionResult UpdateInvoice(int invoiceId)
{
// some code...
return View();
}




[AuthorizeUser(AccessLevels="Create Invoice")]
public ActionResult CreateNewInvoice()
{
// some code...
return View();
}




[AuthorizeUser(AccessLevels="Delete Invoice")]
public ActionResult DeleteInvoice(int invoiceId)
{
// some code...
return View();
}

    Is it possible to do it this way?

    Criteria:

    Every year divisible by 4 is a leap year, except when it is divisible by 100 unless it is divisible by 400. So:

    2004 - leap year - divisible by 4
1900 - not a leap year - divisible by 4, but also divisible by 100
2000 - leap year - divisible by 4, also divisible by 100, but divisible by 400

    February has 29 days in a leap year and 28 when not a leap year

    >2015-02-29

    30 days in April, June, September and November

    2015-04-31

    31 days in January, March, May, July, August, October and December

    1900-02-29

    Test:

    1999-01-32

    The following dates should all pass validation:

    1976-02-29
2000-02-29
2004-02-29
1999-01-31
    2015-02-00

    Range:

    The following dates should all fail validation:

    2015-02-29
2015-04-31
1900-02-29
1999-01-32
2015-02-00

    Range:

    We'll test for dates from 1st Jan 1000 to 31st Dec 2999. Technically the currently used Gregorian calendar only came into use in 1753 for the British Empire and at various years in the 1600s for countries in Europe, but I'm not going to worry about that.

    We'll test for dates from 1st Jan 1000 to 31st Dec 2999. Technically the currently used Gregorian calendar only came into use in 1753 for the British Empire and at various years in the 1600s for countries in Europe, but I'm not going to worry about that.

    Regex to test for a leap year:

    Regex to test for a leap year:

    The years divisible by 400:

    1200|1600|2000|2400|2800
can be shortened to:
(1[26]|2[048])00


if you wanted all years from 1AD to 9999 then this would do it:
(0[48]|[13579][26]|[2468][048])00
if you're happy with accepting 0000 as a valid year then it can be shortened:
([13579][26]|[02468][048])00

    The years divisible by 400:

    1200|1600|2000|2400|2800
can be shortened to:
(1[26]|2[048])00


if you wanted all years from 1AD to 9999 then this would do it:
(0[48]|[13579][26]|[2468][048])00
if you're happy with accepting 0000 as a valid year then it can be shortened:
([13579][26]|[02468][048])00

    The years divisible by 4:

    [12]\d([02468][048]|[13579][26])

    The years divisible by 4:

    [12]\d([02468][048]|[13579][26])

    The years divisible by 100:

    [12]\d00

    The years divisible by 100:

    [12]\d00

    Not divisible by 100:

    [12]\d([1-9]\d|\d[1-9])

    Not divisible by 100:

    [12]\d([1-9]\d|\d[1-9])

    The years divisible by 100 but not by 400:

    ((1[1345789])|(2[1235679]))00

    The years divisible by 100 but not by 400:

    ((1[1345789])|(2[1235679]))00

    Divisible by 4 but not by 100:

    [12]\d([2468][048]|[13579][26]|0[48])

    The leap years:

    divisible by 400 or (divisible by 4 and not divisible by 100)
((1[26]|2[048])00)|[12]\d([2468][048]|[13579][26]|0[48])

    Divisible by 4 but not by 100:

    [12]\d([2468][048]|[13579][26]|0[48])

    Not divisible by 4:

    [12]\d([02468][1235679]|[13579][01345789])

    The leap years:

    divisible by 400 or (divisible by 4 and not divisible by 100)
((1[26]|2[048])00)|[12]\d([2468][048]|[13579][26]|0[48])

    Not a leap year:

    Not divisible by 4 OR is divisible by 100 but not by 400
([12]\d([02468][1235679]|[13579][01345789]))|(((1[1345789])|(2[1235679]))00)

    Not divisible by 4:

    [12]\d([02468][1235679]|[13579][01345789])

    Valid Month and day excluding February(MM-DD):

    ((01|03|05|07|08|10|12)-(0[1-9]|[12]\d|3[01]))|((04|06|09|11)-(0[1-9]|[12]\d|30))
shortened to:
((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30))

    Not a leap year:

    Not divisible by 4 OR is divisible by 100 but not by 400
([12]\d([02468][1235679]|[13579][01345789]))|(((1[1345789])|(2[1235679]))00)

    February with 28 days:

    02-(0[1-9]|1\d|2[0-8])

    Valid Month and day excluding February(MM-DD):

    ((01|03|05|07|08|10|12)-(0[1-9]|[12]\d|3[01]))|((04|06|09|11)-(0[1-9]|[12]\d|30))
shortened to:
((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30))

    February with 29 days:

    02-(0[1-9]|[12]\d)

    February with 28 days:

    02-(0[1-9]|1\d|2[0-8])

    Valid date:

    (leap year followed by (valid month-day-excluding-february OR 29-day-february))
OR
(non leap year followed by (valid month-day-excluding-february OR 28-day-february))


((((1[26]|2[048])00)|[12]\d([2468][048]|[13579][26]|0[48]))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|[12]\d))))|((([12]\d([02468][1235679]|[13579][01345789]))|((1[1345789]|2[1235679])00))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|1\d|2[0-8]))))

    February with 29 days:

    02-(0[1-9]|[12]\d)

    Valid date:

    (leap year followed by (valid month-day-excluding-february OR 29-day-february))
OR
(non leap year followed by (valid month-day-excluding-february OR 28-day-february))


((((1[26]|2[048])00)|[12]\d([2468][048]|[13579][26]|0[48]))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|[12]\d))))|((([12]\d([02468][1235679]|[13579][01345789]))|((1[1345789]|2[1235679])00))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|1\d|2[0-8]))))

    So there you have it a regex for dates between 1st Jan 1000 and 31st Dec 2999 in YYYY-MM-DD format.

    So there you have it a regex for dates between 1st Jan 1000 and 31st Dec 2999 in YYYY-MM-DD format.

    I suspect it can be shortened quite a bit, but I'll leave that up to somebody else.

    I suspect it can be shortened quite a bit, but I'll leave that up to somebody else.

    That will match all valid dates. If you want it to only be valid when it contains just one date and nothing else, then wrap it in ^( )$ like so:

    ^(((((1[26]|2[048])00)|[12]\d([2468][048]|[13579][26]|0[48]))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|[12]\d))))|((([12]\d([02468][1235679]|[13579][01345789]))|((1[1345789]|2[1235679])00))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|1\d|2[0-8])))))$

    If you want it for an optional date entry (ie. it can be blank or a valid date) then add ^$| at the beginning, like so:

    ^$|^(((((1[26]|2[048])00)|[12]\d([2468][048]|[13579][26]|0[48]))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|[12]\d))))|((([12]\d([02468][1235679]|[13579][01345789]))|((1[1345789]|2[1235679])00))-((((0[13578]|1[02])-(0[1-9]|[12]\d|3[01]))|((0[469]|11)-(0[1-9]|[12]\d|30)))|(02-(0[1-9]|1\d|2[0-8])))))$
    小开
    }

    Remove the colon : from the second statement as you are assigning a new value to existing variable.

    myArray = [...]int{11,12,14}
    }
    小开

    dd-mm-yyyy :

    There are two types of assignment operators in go := and =. They are semantically equivalent (with respect to assignment) but the first one is also a "short variable declaration" ( http://golang.org/ref/spec#Short_variable_declarations ) which means that in the left we need to have at least a new variable declaration for it to be correct.

    /^(((0[1-9]|[12]\d|3[01])\-(0[13578]|1[02])\-((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\-(0[13456789]|1[012])\-((19|[2-9]\d)\d{2}))|((0[1-9]|1\d|2[0-8])\-02\-((19|[2-9]\d)\d{2}))|(29\-02\-((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))))$/g

    小开 
    myArray  :=[...]int{12,14,26}

    This method can be useful to validate date in PHP. Current method is for mm/dd/yyyy format. You have to update parameter sequence in checkdate as per your format and delimiter in explode .

        function isValidDate($dt)
{
$dtArr = explode('/', $dt);
if (!empty($dtArr[0]) && !empty($dtArr[1]) && !empty($dtArr[2])) {
return checkdate((int) $dtArr[0], (int) $dtArr[1], (int) $dtArr[2]);
} else {
return false;
}
}
    /strong> variable myArray, which already contains integer values.

    This works:

    myArray = [...]int{11,12,14} // NO error will be produced by this line

    As stated by the previous commenters, := is a type of short-hand and/or the short-form of variable declaration.

    So in the statment above you are doing two things.

      Because, it is assigning the integer array to the existing ( pre-declared / initialized ) variable.

    小开

    Check and validate YYYY-MM-DD date in one line statement

    function isValidDate($date) {
return preg_match("/^(\d{4})-(\d{1,2})-(\d{1,2})$/", $date, $m)
? checkdate(intval($m[2]), intval($m[3]), intval($m[1]))
: false;
}

    The output will be:

    var_dump(isValidDate("2018-01-01")); // bool(true)
var_dump(isValidDate("2018-1-1"));   // bool(true)
var_dump(isValidDate("2018-02-28")); // bool(true)
var_dump(isValidDate("2018-02-30")); // bool(false)
  • You are declaring your variable to be myArray.

    • Day and month without leading zero are allowed. If you don't want to allow this, the regexp should be:

    "/^(\d{4})-(\d{2})-(\d{2})$/"
    小开

    You could also do it like this:

    if (DateTime::createFromFormat('Y-m-d', $date)->format('Y-m-d') === $date) {


// date is correctly formatted and valid, execute some code


}

    This will not only check the format, but also the validity of the date self, since DateTime will create only valid dates and this needs to match the input.

    小开
  • You are assigning an array of integers to the myArray variable.

    • you can use 

    function validateDate($date, $format = 'Y-m-d H:i:s')
{
$d = DateTime::createFromFormat($format, $date);
return $d && $d->format($format) == $date;
}


$date="2012-09-12";
echo validateDate($date, 'Y-m-d'); // true or false
    小开

    The second part of your code fails, because what you are doing here:

    myArray  :=[...]int{11,12,14} //error pointing on this line

    If it is of any help, here is a regex for j-n-Y format (year has to be greater than 2018):

    if (preg_match('/^([1-9]|[1-2][0-9]|[3][0-1])\-([1-9]|[1][0-2])\-(?:20)([1][8-9]|[2-9][0-9])$/', $date)) {
// Do stuff
}
    小开

    [If you use Symfony 4.1.2 try this][1]

      $validDate = explode("-",$request->get('date'));
if (checkdate(filter_var($validDate[1],FILTER_SANITIZE_NUMBER_INT),filter_var($validDate[0],FILTER_SANITIZE_NUMBER_INT),filter_var($validDate[2],FILTER_SANITIZE_NUMBER_INT))){
$date = date_create(filter_var($request->get('date'),FILTER_SANITIZE_SPECIAL_CHARS));
}else{
return $this->redirectToRoute('YOUR_ROUTE');
}
    小开

    Is RE-declaring the existing variable myArray, which already contains integer values.

    From Laravel 5.7 and date format i.e.: 12/31/2019

    function checkDateFormat(string $date): bool
{
return preg_match("/^(0[1-9]|1[0-2])\/(0[1-9]|[1-2][0-9]|3[0-1])\/[0-9]{4}$/", $date);
}
    小开

    Format 2 : $format2 = "31-12-2012";

    if (preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$format1)) {
return true;
} else {
return false;
}


if (preg_match("/^(0[1-9]|[1-2][0-9]|3[0-1])-(0[1-9]|1[0-2])-[0-9]{4}$/",$format2)) {
return true;
} else {
return false;
}
    s a consequence, redeclaration can only appear in a multi-variable short declaration. Redeclaration does not introduce a

    As a side note, redeclaration can only appear in a multi-variable short declaration

    new variable; it just assigns a new value to the original.

    package main


import "fmt"




func main() {
a, b := 1, 2
c, b := 3, 4


fmt.Println(a, b, c)
}

    Quoting from the Language specification:

    Here is a very good example about redeclaration of variables in golang:

    Unlike regular variable declarations, a short variable declaration may https://stackoverflow.com/a/27919847/4418897

    小开
    redeclare variables provided they were originally declared earlier in the same block with the same type, and at least one of the non-blank

    I was searching "how to validate date" and found this solution, Its old but i ll share below method that can be use to validate date in php,

    checkdate('01', '31', '2019')
    小开

    Function to validate generic date format:

    function validateDate($date, $format = 'Y-m-d') {
$d = DateTime::createFromFormat($format, $date);
return $d && $d->format($format) == $date;
}
    variables is new. As a consequence, redeclaration can only appear in a

    Example of execution:

    var_dump(validateDate('2021-02-28')); // true
var_dump(validateDate('2021-02-29')); // false
    小开
    multi-variable short declaration. Redeclaration does not introduce a

    Probably useful to someone:

    $patterns = array(
'Y'           =>'/^[0-9]{4}$/',
'Y-m'         =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])$/',
'Y-m-d'       =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])$/',
'Y-m-d H'     =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])\s(0|[0-1][0-9]|2[0-4])$/',
'Y-m-d H:i'   =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])\s(0|[0-1][0-9]|2[0-4]):?(0|[0-5][0-9]|60)$/',
'Y-m-d H:i:s' =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])\s(0|[0-1][0-9]|2[0-4]):?((0|[0-5][0-9]):?(0|[0-5][0-9])|6000|60:00)$/',
);
echo preg_match($patterns['Y'], '1996'); // true
echo preg_match($patterns['Y'], '19966'); // false
echo preg_match($patterns['Y'], '199z'); // false
echo preg_match($patterns['Y-m'], '1996-0'); // false
echo preg_match($patterns['Y-m'], '1996-09'); // true
echo preg_match($patterns['Y-m'], '1996-1'); // true
echo preg_match($patterns['Y-m'], '1996/1'); // true
echo preg_match($patterns['Y-m'], '1996/12'); // true
echo preg_match($patterns['Y-m'], '1996/13'); // false
echo preg_match($patterns['Y-m-d'], '1996-11-1'); // true
echo preg_match($patterns['Y-m-d'], '1996-11-0'); // false
echo preg_match($patterns['Y-m-d'], '1996-11-32'); // false
echo preg_match($patterns['Y-m-d H'], '1996-11-31 0'); // true
echo preg_match($patterns['Y-m-d H'], '1996-11-31 00'); // true
echo preg_match($patterns['Y-m-d H'], '1996-11-31 24'); // true
echo preg_match($patterns['Y-m-d H'], '1996-11-31 25'); // false
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 2400'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:00'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:59'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:60'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:61'); // false
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:61'); // false
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:6000'); // true
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:60:00'); // true
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:59:59'); // true
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:59:60'); // false
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:60:01'); // false
    小开
    new variable; it just assigns a new value to the original.

    package main


import "fmt"




func main() {
a, b := 1, 2
c, b := 3, 4


fmt.Println(a, b, c)
}

    A more pragmatic pattern could be like this

    $date="2012-09-12";


if (preg_match("/^(20[0-9]{2})-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)) {
return true;
} else {
return false;
}

    Here is a very good example about redeclaration of variables in golang:

    Which will prevent to put 9999-09-12 such values.

    小开

    The below ensures digits YYYY(1900-2099)-MM(01-12)-DD(01-31) as well as utilises checkdate() function for date correctness e.g. 29 Feb:

    $date_pattern = '/^(19|20)\d{2}\-(0[1-9]|1[0-2])\-(0[1-9]|[12][0-9]|3[01])$/';


if (empty($date) || (!preg_match("$date_pattern", $date, $m) || (!checkdate($m[2], $m[3], $m[1])))) {
$echo 'Invalid Start date e.g. YYYY-MM-DD';
}

    To change date patterns and year range:

    // pattern DD/MM/YYYY where DD (01-31), MM (01-12) and YYYY (1950-2099) & have to be digits - replace checkdate () with !checkdate($m[2], $m[1], $m[3]

    // To extend year range e.g. 1900-2099 /^(0[1-9]|[12][0-9]|3[01])/(0[1-9]|1[0-2])/(19|20)\d{2}$/ - replace checkdate () with !checkdate($m[2], $m[1], $m[3]

    小开

    Easiest way is to convert it to desired format:

    $date="2012-09-12";
$date=strtotime($date);
if($date != NULL){
/*Valid Date*/
$date=date("Y-m-d",$date);
return true;
}else{
/*InValid Date*/
return false;
};

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