Question

I would like to check for a valid date in ‘mm/dd/yyyy’ format. When I call the function below with isValidDateTime('12/10/2012'), it returns false. Could you please let me know what could be wrong?

function isValidDateTime($dateTime)
{
    if (preg_match("/^(\d{2})/(\d{2})/(\d{4}) ([0-5][0-9]):([0-5][0-9]):([01][0-9]|2[0-3])$/", $dateTime, $matches)) {
        if (checkdate($matches[1], $matches[3], $matches[2])) {
            return true;
        }
    }

    return false;
}

Answer 1

Here is a simpler way to accomplish your date validation … it doesn’t verify the mm/dd/yyyy format, but it doesn’t need to.

The DateTime constructor throws an exception if passed an invalid date string. Once you have a valid date, you can use DateTime::format() to output the date in any format you want.

$str = 'bad date';

try {
  $date = new DateTime($str);
  echo $date->format('m/d/Y');
  // do stuff
} catch(Exception $e) {
  echo "The date '$str' is not valid";
}