PHP formats time days ago, minutes ago, etc.

class DateFormat
{
 private static $_DIFF_FORMAT = array(
 'DAY' => '%s days ago',
 'DAY_HOUR' => '%s days %s hours ago',
 'HOUR' => '%s hours',
 'HOUR_MINUTE' => '%s hours %s minutes ago',
 'MINUTE' => '%s minutes ago',
 'MINUTE_SECOND ' => '%s minutes %s seconds ago',
 'SECOND' => '%s seconds ago',
 );

 /**
 * Friendly formatted time
 *
 * @param int time
 * @param array $formats
 * @return string
*/
 public static function diff($timestamp, $formats = null)
 {
 if ($formats == null) {
 $formats = self::$_DIFF_FORMAT;
 }
 /* Calculate the time difference*/
 $seconds = time() - $timestamp;
 $ minutes = floor($seconds / 60);
 $hours = floor($minutes / 60);
 $days = floor($hours / 24);

 if ($days > 0) {
 $diffFormat = ' DAY';
 } else {
 $diffFormat = ($hours > 0) ? 'HOUR' : 'MINUTE';
 if ($diffFormat == 'HOUR') {
 $diffFormat .= ($minutes > 0 && ($minutes - $hours * 60) > 0) ? '_MINUTE' : '';
 } else {
 $diffFormat = (($seconds - $minutes * 60) > 0 && $minutes > 0)
 ? $diffFormat.'_SECOND' : 'SECOND';
 }
 }

 $dateDiff = null;
 switch ($diffFormat) {
 case 'DAY':
 $dateDiff = sprintf($formats[$diffFormat], $days);
 break;
 case 'DAY_HOUR':
 $dateDiff = sprintf($formats[$diffFormat], $days, $hours - $days * 60);
 break;
 case 'HOUR':
 $dateDiff = sprintf($formats[$diffFormat], $hours);
 break;
 case 'HOUR_MINUTE':
 $dateDiff = sprintf($formats[$diffFormat], $hours, $minutes - $hours * 60);
 break ;
 case 'MINUTE':
 $dateDiff = sprintf($formats[$diffFormat], $minutes);
 break;
 case 'MINUTE_SECOND':
 $dateDiff = sprintf($formats[$diffFormat], $minutes, $ seconds - $minutes * 60);
 break;
 case 'SECOND':
 $dateDiff = sprintf($formats[$diffFormat], $seconds);
 break;
 }
 return $dateDiff;
 }
}

 echo DateFormat::diff('1310455823');
/* 33 minutes 47 seconds ago*/

Days, minutes, PHP