IMAP date

PHP
1

The imap code below displays the date like this:
Sat, 18 Feb 2012 19:22:02 +0100
I want the date to be displayed like this instead:
2012-02-18

Any idea how I can achieve this?

Thanks in advance

<?php
date_default_timezone_set ("Europe/Stockholm");
/* connect to mail */
$hostname = '{xxx.xxxx.com:143/notls}INBOX';
$username = 'xxxxx@xxxxx.com';
$password = 'xxxxxx';

/* try to connect */
$inbox = imap_open($hostname,$username,$password) or die('Anslutning till mail misslyckades: ' . imap_last_error());

/* grab emails */
$emails = imap_search($inbox,'ALL');

/* if emails are returned, cycle through each... */
if($emails) {

  /* begin output var */
  $output = '';

  /* put the newest emails on top */
  rsort($emails);

  /* for every email... */
  foreach($emails as $email_number) {

    /* get information specific to this email */
    $overview = imap_fetch_overview($inbox,$email_number,0);
    $message = imap_fetchbody($inbox,$email_number,2);
	$date = date('d m Y');
    $swedate = $overview[0]->date;
    /* output the email  information */
    $output.= '<li>';
	$output.= '<a href="#"><strong>'.$swedate.'</strong> ';
    $output.= ''.$overview[0]->subject.'<br> ';
    $output.= '<small> Fr&aring;n: '.$overview[0]->from.'</small></a>';
    $output.= '</li>';


  }

  echo $output;

}

/* close the connection */
imap_close($inbox);


?>
2 

$swedate = date("Y-m-d", strtotime($overview[0]->date));

I think that is what you are looking for.