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

Question

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?

Tinct

Regex is not enough to validate a date. After regex you should also use one of these two: date("Y-m-d", strtotime("2012-09-12"))=="2012-09-12"; or PHP's checkdate ( int $month , int $day , int $year ). – Pyroligneous

Im not trying to validate it at this point, i just want to make sure its in the YYYY-MM-DD format. – Tinct

For a user entered value, what better "point" in time to validate other than right after the regex, on form submission (so you can display an error)? – Pyroligneous

Fair point, could save a hickup later. – Tinct

Answer 1

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;
}

Intermix

return (bool)preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date); – Pyroligneous

Why has this been marked as the correct answer? This returns true for a number of invalid dates like 2016-02-30 and 2016-09-31 – Carola

This question is about how to check a date format (YYYY-MM-DD), and an answer marked as accepted is not always the best answer, it just means that it worked for the person who asked, read this beautiful tour: stackoverflow.com/tour . – Donothingism

@Carola old post I know but agree with Stramin - this question asks about format validation - not actual date validation – Clarino

validate datetime preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])T(0[1-9]|1[0-9]|2[0-4]):(0[1-9]|1[0-9]|2[0-9]|3[0-9]|4[0-9]|5[0-9]|6[0-9])$/",$dateTime) – Agglutination

Should be as simple as this (one of my answers properly formatted down the page): $date_pattern = '/^(19|20)\d{2}\-(0[1-9]|1[0-2])\-(0[1-9]|[12][0-9]|3[01])$/'; 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'; } – Counterweight

Not a correct answer. I tried 0~9 numbers without dashes and it returns as true. – Alethiaaletta

Answer 2

It's probably better to use another mechanism for this.

The modern solution, with DateTime:

// For PHP >= 8.2
$dt = DateTime::createFromFormat("Y-m-d", $date);
return $dt !== false && $dt::getLastErrors() === false;

// For PHP < 8.2
$dt = DateTime::createFromFormat("Y-m-d", $date);
return $dt !== false && !array_sum($dt::getLastErrors());

This validates the input too: $dt !== false ensures that the date can be parsed with the specified format and the array_sum trick is a terse way of ensuring that PHP did not do "month shifting" (e.g. consider that January 32 is February 1). See DateTime::getLastErrors() for more information.

Old-school solution with explode and checkdate:

list($y, $m, $d) = array_pad(explode('-', $date, 3), 3, 0);
return ctype_digit("$y$m$d") && checkdate($m, $d, $y);

This validates that the input is a valid date as well. You can do that with a regex of course, but it's going to be more fuss -- and February 29 cannot be validated with a regex at all.

The drawback of this approach is that you have to be very careful to reject all possible "bad" inputs while not emitting a notice under any circumstances. Here's how:

• explode is limited to return 3 tokens (so that if the input is "1-2-3-4", $d will become "3-4")
• ctype_digit is used to make sure that the input does not contain any non-numeric characters (apart from the dashes)
• 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

Uzzia

+1, always used DateTime and never heard about checkdate... shame on me. – Capitalistic

@k102: DateTime can also do this. I just finished fleshing out the answer, have a look again if you 'd like. – Uzzia

Looking at the PHP manual, it looks like the first solution will validate incomplete dates (filling out the missing values from the current date). – Supercolumnar

Another problem with solution #1: "non-existant values roll over", e.g. 2001-02-31 becomes 2001-03-03. (Though the OP hasn't asked explicitly that this isn't possible.) – Supercolumnar

@user2428118: Did you try solution #1 exactly as given, or just the first line? Did you click the link I give to the documentation for getLastErrors? – Uzzia

@Uzzia Sorry, hadn't looked through the comments on the getLastErrors page. – Supercolumnar

DateTime::createFromFormat("Y-m-d", $date); This will pass a single digit month also. For example, 2021-3-23 would be valid, while the user apparently is looking for only allowing 2021-03-23 – Rancorous

I will suggest this for PHP 8: $dt = DateTime::createFromFormat("Y-m-d", $date); return $dt !== false && (false === $dt::getLastErrors() || !array_sum($dt::getLastErrors())); – Alyce

Answer 3

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

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

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

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

dd/mm/yyyy : /^(((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

dd-mm-yyyy : /^(((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

Cundiff

The above all work for dates from 1900 to 9999 which is what is needed most of the time and is 74 characters shorter than my attempt (re the yyyy-mm-dd format). if you want dates pre-1900, then a minor tweak to Shyju answer will allow from year 1000 and is another 23 characters shorter: ^((([1-9]\d{3})\-(0[13578]|1[02])\-(0[1-9]|[12]\d|3[01]))|(((19|[2-9]\d)\d{2})\-(0[13456789]|1[012])\-(0[1-9]|[12]\d|30))|(([1-9]\d{3})\-02\-(0[1-9]|1\d|2[0-8]))|(([1-9]\d(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))\-02\-29))$ – Carola

Answer 4

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

30 days in April, June, September and November

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

Test:

The following dates should all pass validation:

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

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.

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 4:

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

The years divisible by 100:

[12]\d00

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

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])

Not divisible by 4:

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

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)

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 28 days:

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.

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:

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

Carola

That is a heroic expression, and explained very well. – Twickenham

Do you have strong proof that it will pass every valid case and fail on every invalid case? – Sandal

@Md Ashraful Islam No – Carola

@Carola Altough no problem, we are using it in our website. I hope no problem will occur. – Sandal

@Md Ashraful Islam - We also use it and have not had any problems with it so far – Carola

Answer 5

You can make it this way:

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

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.

Capitalistic

The dateTime technique used here will return true for a date like 2016-05-44 which is not an actual date – Wonderment

This is not a good example especially if you want to get date( Y-m-d ). Example: 0175-44-19927 will pass. – Esposito

I don't see ^ and $. – Bacteria

Answer 6

I know that this is a old question. But I think I have a good solution.

$date = "2016-02-21";
$format = "Y-m-d";

if(date($format, strtotime($date)) == date($date)) {
    echo "true";
} else {
    echo "false";
}

You can try it. If you change the date to 21.02.2016 the echo is false. And if you change the format after that to d.m.Y the echo is true.

With this easy code you should be able to check which date-format is used without checking it by the regex.

Maybe there is a person who will test it on every case. But I think my idea is generally valid. For me it seems logical.

Searcy

I don't think you need date() around $date on the if line. if(date($format, strtotime($date)) == $date) - should be sufficient – Doubletalk

This seems to work fine and it handles leap years ok – Flooring

Answer 7

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

Vanillin

'1996-11-31 24:00'); // true, really? Moreover, sometimes there is 61 seconds in a minute, see: en.wikipedia.org/wiki/Leap_second – Carisa

Answer 8

You can use a preg_match with a checkdate php function

$date  = "2012-10-05";
$split = array();
if (preg_match ("/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/", $date, $split))
{
    return checkdate($split[2], $split[3], $split[1]);
}

return false;

Attlee

return preg_match ("/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/", $date, $split)) && checkdate($split[2],$split[3],$split[1]) ; – Pyroligneous

Answer 9

Function to validate generic date format:

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

Example of execution:

var_dump(validateDate('2021-02-28')); // true
var_dump(validateDate('2021-02-29')); // false

Chancelor

Please put your answer always in context instead of just pasting code. See here for more details. Please also edit your answer to contain all parts of the code in the markdown block – Holguin

Source : php.net/manual/en/function.checkdate.php#113205 – Alyce

Answer 10

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 )

Legged

Answer 11

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.

Elsie

Answer 12

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

Pontone

Answer 13

Format 1 : $format1 = "2012-12-31";

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;
}

Bestiality

Answer 14

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]

Counterweight

Answer 15

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

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

Service

Answer 16

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';
    }

Shifflett

Answer 17

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)

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})$/"

Capello

Answer 18

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')

Interrogatory

Answer 19

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');

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

Sheehy

This regex is unnecessarily complicated. 0[1-9]|1[0-2] matches month 01-12 and 0[1-9]|[12][0-9]|3[01] matches day 01-31. – Gonococcus

Excuse me while i vomit – Merbromin

Answer 20

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)

Rose

Your rgex is wrong, it will not match 1980-01-01 but will match 2100-02-29 – Carisa

Answer 21

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
}

Fontanel

Answer 22

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);
}

Lipsey

Answer 23

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;
};

Materialism

Answer 24

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;
        }
    }

Exquisite

Answer 25

[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');
        }

Incautious

Answer 26

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;
}

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

Convincing

Answer 27

One-liner solution for checking the correctness of the date using DateTime and > PHP 8.0.

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

Pirali