Formats seconds to an 'ago' string.

formatSince.php

// Formats seconds to an 'ago' string.
// Example: formatSince(3720); returns '1 hour and 2 minutes ago'.

function formatSince($seconds)
  {
    if($seconds === 0) { return 'Now'; } else if($seconds < 0) { return false; }

    $t = array(
      'year' => 31556926,
      'month' => 2629743,
      'week' => 604800,
      'day' => 86000,
      'hour' => 3600,
      'minute' => 60,
      'second' => 1
    );

    $index = 0; $count = count($t) - 1; $keys = array_keys($t);

    foreach($t as $key => $i)
    {
      $index++;

      if($seconds <= $i) continue;

      $n = $count >= $index ? $keys[$index] : NULL;
      $f = floor($seconds / $i);
      $s = $n ? floor(($seconds - ($f * $i)) / $t[$n]) : 0;

      return $f . ' ' . $key . ($f == 1 ? '' : 's') .
      ($s > 0 ? (' and ' . $s . ' ' . $n . ($s == 1 ? '' : 's')) : '') . ' ago';
    }

    return false;
  }