PHP | checkdate() Function

The checkdate() function is a built-in function in PHP which checks the validity of the date passed in the arguments. It accepts the date in the format mm/dd/yyyy. The function returns a boolean value. It returns true if the date is a valid one, else it returns false. 

Syntax: 

checkdate ( $month, $day, $year )

Parameters: The function accepts three mandatory parameters as shown above and described below:  

1. $month – This parameter specifies the month. The month has to be in between 1 to 12 for a valid date.
2. $day – This parameter specifies the day. The day can be in range 1-31 depending on the month entered for it to be a valid day. In case of a leap year, the day is in range 1-29 and for a non-leap year the day is in range 1-28.
3. $year – This parameter specifies the year. The year has to be in range 1-32767 inclusive depending on the $month and $day for it to be a valid date.

Return Value: The function returns a boolean value. It returns true if the passed date is a valid date. It returns false if the passed date is not a valid one. 
Examples:

Input : $month = 12 $day = 31 $year = 2017
Output : true

Input : $month = 2 $day = 29 $year = 2016
Output : true 

Input : $month = 2 $day = 29 $year = 2017
Output : false

Below programs illustrate the checkdate() function in PHP :
Program 1: The program below check if the date is a valid one or not. 

php

<?php
// PHP program to demonstrate the checkdate() function

$month = 12;
$day = 31;
$year = 2017;

// returns a boolean value after validation of date
var_dump(checkdate($month, $day, $year));

?>

Output: 

bool(true)

Program 2: The program below check if the date is a valid one or not in case of a leap year and non-leap year.  

php

<?php
// PHP program to demonstrate the checkdate() function
// in case of leap year

$month = 2;
$day = 29;
$year = 2016;

// returns a boolean value after validation of date
// leap year
var_dump(checkdate($month, $day, $year));


$month = 2;
$day = 29;
$year = 2017;

// returns a boolean value after validation of date
// non-leap year
var_dump(checkdate($month, $day, $year));

?>

Output: 

bool(true)
bool(false)

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.