How to Check If A String Is A Date in PHP

In this article, you will learn how to check if a string is a date or not in PHP.

Let’s say you have 2 string variables.

// A string variable named 'a' with value "2021-03-01"
$a = "2021-03-01";

// A string variable named 'b' with value "2021-13-01"
$b = "2021-13-01";

Check If A String Is A Date

In order to check if a string is a date or not, you can use the strtotime() method.

// A string variable named 'a' with value "2021-03-01"
$a = "2021-03-01";

// A string variable named 'b' with value "2021-13-01"
$b = "2021-13-01";

// This function checks if a string is a valid date or not
function checkString($string) {
  
  // If the string can be converted to UNIX timestamp
  if (strtotime($string)) {
      
      // Display valid date message
      echo "The string $string is a valid date. <br/>" ;
  }
  
  // Else if the string cannot be converted to UNIX timestamp
  else {
      // Display not valid date message
      echo "The string $string is not a valid date. <br/>";
  }
  
}

checkString($a);
checkString($b);

Note: The strtotime() method functions by parsing an English datetime string into a UNIX timestamp.