使用javascript将时间转换成今天，昨天，前天等格式

function transDate() {    var $time =document.getElementById("share-time");    var date = $time.innerHTML.trim();    var tt = new Date(parseInt(date));    var days = parseInt((new Date().getTime() - date) / 86400000);    var today = new Date().getDate();    var year = tt.getFullYear();    var mouth = tt.getMonth() + 1;    var day = tt.getDate();    var time = tt.getHours() < 10 ? "0" + tt.getHours() : tt.getHours();    var min = tt.getMinutes() < 10 ? "0" + tt.getMinutes() : tt.getMinutes();    var result, offset;　　　　　　　offset = Math.abs(today - day);　　　　if (days < 4&&offset<4) {　　　　　　　if (offset === 0) {        result = "今天" + time + ":" + min;      } else if (offset === 1) {        result = "昨天" + time + ":" + min;      } else if (offset === 2) {        result = "前天" + time + ":" + min;      }    } else {      result = year + "-" + mouth + "-" + day + " " + time + ":" + min;    }    $time.innerHTML = result;  }  transDate();