JS function for displaying tweet time

gistfile1.js

function getTweetTime(timestamp)
{
  var time = (Date.parse(timestamp)/1000);
  time = Math.round((((new Date()).getTime() / 1000)-time)/60);

   if (time >= 60) {
       var hours = Math.round(time / 60);

        if (hours == 1) {
            return "sent " + hours + " hour ago";
        }
   
   if (hours >= 48) {
           var days = Math.round(hours/24);
            return "sent " + days + " days ago";
        }
        return "sent " + hours + " hours ago";
    }

    if (time < 60) {
        if (time < 1) {
            return "sent secs ago";
        }
        if(time == 1)
          {
            return "sent a minute ago";
          }
        return "sent " + time  + " mins ago";
    }
}