Date Validation: checking entered date if not exist function checkdate

Validate a calendar date with checkdate()

Validate the three numeric parts first, then pass month, day and year to checkdate(). This rejects impossible dates such as 31 February.

$month = filter_input(INPUT_POST, 'month', FILTER_VALIDATE_INT);
$day = filter_input(INPUT_POST, 'day', FILTER_VALIDATE_INT);
$year = filter_input(INPUT_POST, 'year', FILTER_VALIDATE_INT);

if ($month && $day && $year && checkdate($month, $day, $year)) {
    echo 'Valid date';
} else {
    echo 'Invalid date';
}

<?php
echo checkdate(12,31,2017); // Output 1 
echo var_dump(checkdate(12,31,2017)); // Output bool(true) 
echo var_dump(checkdate(29,02,2017)); // Output bool(false) 
echo var_dump(checkdate(06,31,2023)); // Output bool(false) 
?>

Syntax

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

Many times we have to check the date entered are in correct format or not. The combination of entered month date and year by a user has to be a valid date to use in our applications. Even if we give a selection or a drop down list box to select a date we have to check the combination of month, day and year selection is valid or not. User may select 29th Feb 2005 (which is not a leap year ) or it may select 31st Nov of any year. So the combination has to be checked.

Using checkdate()

We will try checkdate() function which takes care of leap year checking also. This function validates the date and returns true if date is correct or false if date is wrong or does not exist. Here is the format

If you are using the drop down date combination for selection or asking to enter date in a format, better to validate date by using checkdate function.

Here is the case where checkdate will return false

$m='11';
$d='31';
$y='05';
If(!checkdate($m,$d,$y)){
echo 'invalid date'; 
}else {
echo "Entry date is correct";
}

Input date from a text field

If we are asking the user to enter date in a text field then we have to break the entered date value by using explode function and then use the checkdate function to validate the date data ( of user ). Here we are collecting the user entered date value of a form posted by POST method.

$dt = filter_input(INPUT_POST, 'dt');
$dt = $dt ?: '02/28/2007'; // m/d/Y example
$arr = explode('/', $dt);
if (count($arr) === 3) {
    [$mm, $dd, $yy] = array_map('intval', $arr);
    echo checkdate($mm, $dd, $yy) ? 'Entry date is correct' : 'Invalid date';
} else {
    echo 'Use m/d/Y format';
}

If the input uses d/m/Y instead, map the array positions accordingly:

$dd=$arr[0]; // first element of the array is date
$mm=$arr[1]; // second element is month
$yy=$arr[2]; // third element is year

Input date from a calendar

We don't expect a wrong entry by user when they select a date from a Calendar. However it is better to check the date as user can change the dates after selecting from a calendar by using the above code for textbox.

How to pass date ( to text field) by using calendar using PHP & JavaScript

How to pass date ( to text field) by using a calendar using JQuery UI

Date Validation using createFromFormat()

We can create date objects by using createFromFormat() by entering date and format used.

<?php
function Date_validate($input_date, $format = 'd-m-Y')
{
    $date_obj = DateTime::createFromFormat($format, $input_date);
    return $date_obj && $date_obj->format($format) == $input_date;
}

echo Date_validate('12-12-2017'); // Output is 1
echo var_dump(Date_validate('12-12-2017')); // Output is bool(true)
echo var_dump(Date_validate('31-11-2017')); // Output is bool(false)
?>

Using date_get_last_errors()

Getting error or warning messages by using date_get_last_errors().

$date = DateTime::createFromFormat('d/m/Y', '01/13/2019'); 
// change above input  date for different messages. //
$errors = DateTime::getLastErrors();
if (!empty($errors['warning_count'])) {
    echo "Strictly speaking, input date is invalid! ( Warning ) ";
}
if (!empty($errors['error_count'])) {
    echo "input date is invalid! ( error ) ";
}

//echo "<br>Input date is : ".$date->format('Y-m-d H:i:s');

01/13/2019 does not match d/m/Y. createFromFormat() may normalize the value, so always inspect getLastErrors() before accepting the result.

For completely invalid text such as Wrong data, parsing fails; treat a false return value or reported errors as invalid input.

PHP Date Functions Timestamp in PHP Displaying calendar for selection of date by user

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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Mat	09-02-2009
how to compare the data entered by the user to the data in the database?

smo	10-02-2009
It can be used in a sql query. A link is added now on this at the end of the tutorial above.

jisha	28-06-2009
how to check a date already entered in database is within the range of a date and duration currently entered by a user?

smo	29-06-2009
In SQL section you can read this article on how to get record between two dates.

tonier	04-09-2009
Just remember this, in SQL, valid format is 'Y-m-d' and day and month must be in 2 digits char.

Mohammad	17-08-2013
How To Find Days From Two Date ? Is there any specific function like floor or else?

ikram	02-05-2013
send email befor one day to friends birthday

checkdate() : Checking a valid date entered by user in PHP