PHP Timestamp until "hours ago" trouble

Question

I need to determine the "time ago" timestamp of the posted comment/s in our site. my boss wants it to display until hours only. so it should display "48 hours ago" instead of "2days ago" or 480hours instead of "20days ago".

here's the code that I found but I don't know how to do it until hours only.

 date_default_timezone_set('Asia/Taipei');
 class Cokidoo_DateTime extends DateTime {

    protected $strings = array(
        'y' => array('1 year ago', '%d years ago'),
        'm' => array('1 month ago', '%d months ago'),
        'd' => array('1 day ago', '%d days ago'),
        'h' => array('1 hour ago', '%d hours ago'),
        'i' => array('1 minute ago', '%d minutes ago'),
        's' => array('now', '%d secons ago'),
    );

    /**
     * Returns the difference from the current time in the format X time ago
     * @return string
     */
    public function __toString() {
        $now = new DateTime('now');
        $diff = $this->diff($now);

        foreach($this->strings as $key => $value){
            if( ($text = $this->getDiffText($key, $diff)) ){
                return $text;
            }
        }
        return '';
     }

    /**
     * Try to construct the time diff text with the specified interval key
     * @param string $intervalKey A value of: [y,m,d,h,i,s]
     * @param DateInterval $diff
     * @return string|null
     */
     protected function getDiffText($intervalKey, $diff){
        $pluralKey = 1;
        $value = $diff->$intervalKey;
        if($value > 0){
        if($value < 2){
            $pluralKey = 0;
            }
            return sprintf($this->strings[$intervalKey][$pluralKey], $value);
        }
        return null;
    }
 }
echo $date = new Cokidoo_Datetime('2012-11-28 0:59:44');

Answer 1

If you have timestamp of the posted date, it is (or can be) represented as int

$now = time();  //current Unix timestamp  in seconds
$hours = ceil(($now - $posted_time)/3600)

Answer 2

in __toString() simple way to adapt the code above, replace foreach block to :

$hours = $diff->format('h');
return $hours > 1 ? $hours . ' hour ago' : $hours . ' hours ago';

Answer 3

Working example : Your class modified to return difference in hours only.

<?php
class Cokidoo_DateTime extends DateTime {
    public function __toString() {
        $now = new DateTime('now');
        $diff = $this->diff($now);        
        return $this->getHours($diff);
     }

     function getHours($diff) {
        $hours =  ($diff->d * 24) + $diff->h; 
        return (string)$hours;
     }
 }
echo $date = new Cokidoo_Datetime('2012-11-28 0:59:44');
?>

Answer 4

'd' => array('24 hours ago', '%d hours ago'),

protected function getDiffText($intervalKey, $diff){
        $pluralKey = 1;
        $value = $diff->$intervalKey;
        if($value > 0){
        if($value < 2){
            $pluralKey = 0;
            }
            if($intervalKey == "d")
            {
            return sprintf($this->strings[$intervalKey][$pluralKey], $value*24);
            }
            return sprintf($this->strings[$intervalKey][$pluralKey], $value);
        }
    return null;
}

}