如何把时间长度(秒)转换成可读的形式

function getDuration(lasttime) { var seconds = ( Date.now() / 1000 | 0 ) - lasttime; if (seconds > 60*2) { if (seconds > 3600*2) { if (seconds > 3600*24*2) { if (seconds > 3600*24*7*2) { if (seconds > 3600*24*30*2) { if (seconds > 3600*24*365*2) { return (seconds / (3600*24*365) | 0) + " years"; } return (seconds / (3600*24*30) | 0) + " months"; } return (seconds / (3600*24*7) | 0) + " weeks"; } return (seconds / (3600*24) | 0) + " days"; } return (seconds / 3600 | 0) + " hours"; } return (seconds / 60 | 0) + " minutes"; } return (seconds) + " seconds"; }