簡述php輸出指定時間以前時間格式的方法

function ago($time) {
 $time = strtotime($time);
 $delta = time() - $time;
 if ($delta < 60) {
  return &#39;less than a minute ago.&#39;;
 } else if ($delta < 120) {
  return &#39;about a minute ago.&#39;;
 } else if ($delta < (45 * 60)) {
  return floor($delta / 60) . &#39; minutes ago.&#39;;
 } else if ($delta < (90 * 60)) {
  return &#39;about an hour ago.&#39;;
 } else if ($delta < (24 * 60 * 60)) {
  return &#39;about &#39; . floor($delta / 3600) . &#39; hour(s) ago.&#39;;
 } else if ($delta < (48 * 60 * 60)) {
  return &#39;1 day ago.&#39;;
 } else {
  return floor($delta / 86400) . &#39; days ago.&#39;;
 }
}