Works out the time since, takes a an argument in unix time (seconds)

TimeSince.php

  function time_since($original) {
    // array of time period chunks
    $chunks = array(
      array(60 * 60 * 24 * 365 , 'year'),
      array(60 * 60 * 24 * 30 , 'month'),
      array(60 * 60 * 24 * 7, 'week'),
      array(60 * 60 * 24 , 'day'),
      array(60 * 60 , 'hour'),
      array(60 , 'minute'),
    );

    $today = time(); /* Current unix time  */
    $since = $today - $original;

    // $j saves performing the count function each time around the loop
    for ($i = 0, $j = count($chunks); $i < $j; $i++) {

      $seconds = $chunks[$i][0];
      $name = $chunks[$i][1];

      // finding the biggest chunk (if the chunk fits, break)
      if (($count = floor($since / $seconds)) != 0) {
        // DEBUG print "<!-- It's $name -->\n";
        break;
      }
    }

    $print = ($count == 1) ? '1 '.$name : "$count {$name}s";

    if ($i + 1 < $j) {
      // now getting the second item
      $seconds2 = $chunks[$i + 1][0];
      $name2 = $chunks[$i + 1][1];

      // add second item if it's greater than 0
      if (($count2 = floor(($since - ($seconds * $count)) / $seconds2)) != 0) {
        $print .= ($count2 == 1) ? ', 1 '.$name2 : ", $count2 {$name2}s";
      }
    }
    return $print;
  }