[php] A non well formed numeric value encountered

I have a form that passes two dates (start and finish) to a PHP script that will add those to a DB. I am having problems validating this. I keep getting the following errors

A non well formed numeric value encountered

This is when I use the following

date("d",$_GET['start_date']);

But when I use the strtotime() function as advised by many sites I get a unix timestamp date of 1/1/1970. Any ideas how I can get the correct date?

if $_GET['start_date'] is a string then convert it in integer or double to deal numerically.

$int = (int) $_GET['start_date']; //Integer
$double = (double) $_GET['start_date']; //It takes in floating value with 2 digits

If the error is at the time of any calculation, double check that the values does not contains any comma(,). Values must be only in integer/ float format.

This is an old question, but there is another subtle way this message can happen. It's explained pretty well here, in the docs.

Imagine this scenerio:

try {
  // code that triggers a pdo exception
} catch (Exception $e) {
  throw new MyCustomExceptionHandler($e);
}

And MyCustomExceptionHandler is defined roughly like:

class MyCustomExceptionHandler extends Exception {
  public function __construct($e) {
    parent::__construct($e->getMessage(), $e->getCode());
  }
}

This will actually trigger a new exception in the custom exception handler because the Exception class is expecting a number for the second parameter in its constructor, but PDOException might have dynamically changed the return type of $e->getCode() to a string.

A workaround for this would be to define you custom exception handler like:

class MyCustomExceptionHandler extends Exception {
  public function __construct($e) {
    parent::__construct($e->getMessage());
    $this->code = $e->getCode();
  }
}

This helped me a lot -

$new_date = date_format(date_create($old_date), 'Y-m-d');

Here, date_create() provides you a date object for a given date & date_format() will set it in a given format.

for example,

<?php
    $date = date_create("13-02-2013");  // DateTime Object ( [date] => 2013-02-13 00:00:00.000000 [timezone_type] => 3 [timezone] => America/New_York )
    echo date_format($date,"Y-m-d");    // 2013-02-13
?>

You need to set the time zone using date_default_timezone_set().

This error occurs when you perform calculations with variables that use letters combined with numbers (alphanumeric), for example 24kb, 886ab ...

I had the error in the following function

function get_config_bytes($val) {
    $val = trim($val);
    $last = strtolower($val[strlen($val)-1]);       
    switch($last) {
        case 'g':
            $val *= 1024;
        case 'm':
            $val *= 1024;
        case 'k':
            $val *= 1024;
    }
    return $this->fix_integer_overflow($val);
}

The application uploads images but it didn't work, it showed the following warning:

Solution: The intval() function extracts the integer value of a variable with alphanumeric data and creates a new variable with the same value but converted to an integer with the intval() function. Here is the code:

function get_config_bytes($val) {
    $val = trim($val);
    $last = strtolower($val[strlen($val)-1]);
    $intval = intval(trim($val));
    switch($last) {
        case 'g':
            $intval *= 1024;
        case 'm':
            $intval *= 1024;
        case 'k':
            $intval *= 1024;
    }
    return $this->fix_integer_overflow($intval);
}

I ran into this same situation (in my case with a date value in a custom PHP field in a Drupal view), and what worked for me was using intval instead of strtotime to turn the value into an integer - because it basically was a timestamp, but in the form of a string rather than an integer. Obviously that won't be the case for everyone, but it might be worth a try.

$_GET['start_date'] is not numeric is my bet, but an date format not supported by strtotime. You will need to re-format the date to a workable format for strtotime or use combination of explode/mktime.

I could add you an example if you'd be kind enough to post the format you currently receive.