只有当日期小于另一个时才运行函数

我建立了一个计数(上下)日期的计数器。我只想让计数器运行下来，一旦它达到当前日期或更晚，就完全停止运行。现在它提醒说日期已经到了，但即使已经到了，它也会继续计数。

这是计数器的JSFiddle。

布尔值

  if(tDate == eDate) {
    alert('Today is the event!');
    return false;
    // clearTimeout( countDown.prototype.update() );
  } else {
    counter();
  }

完整代码

$(document).ready(function() {
  var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
  var d = new Date();
  var month = monthNames[d.getMonth()];
  var day = d.getUTCDate();
  var year = d.getUTCFullYear();
  var eMonth = $("#d-month").html();
  var eDay = $("#d-day").html();
  var eYear = $("#d-year").html();
  var tDate = month + " " + day + " " + year;
  var eDate = eMonth + " " + eDay + " " + eYear;
  alert("today's date: " + tDate + " event's date: " + eDate);
  if(tDate == eDate) {
    alert('Today is the event!');
    return false;
    // clearTimeout( countDown.prototype.update() );
  } else {
    counter();
  }
  function counter() {
    function countDown(initDate, id) {
      this.counterDate = new Date(initDate);
      this.update();
    }
    countDown.prototype.calculateUnit=function(secDiff, unitSeconds){
      var tmp = Math.abs((tmp = secDiff/unitSeconds)) < 1? 0 : tmp;
      return Math.abs(tmp < 0 ? Math.ceil(tmp) : Math.floor(tmp));
    }
    countDown.prototype.calculate=function(){
      var secDiff = Math.abs(Math.round(((new Date()) - this.counterDate)/1000));
      this.days = this.calculateUnit(secDiff,86400);
      this.hours = this.calculateUnit((secDiff-(this.days*86400)),3600);
      this.mins = this.calculateUnit((secDiff-(this.days*86400)-(this.hours*3600)),60);
      this.secs = this.calculateUnit((secDiff-(this.days*86400)-(this.hours*3600)-(this.mins*60)),1);
    }
    countDown.prototype.update=function(){ 
      this.calculate();
      $("#countdown-day").html(this.days + (this.days == 1));
      $("#countdown-hour").html(this.hours + (this.hours == 1));
      $("#countdown-min").html(this.mins + (this.mins == 1));
      $("#countdown-sec").html(this.secs + (this.secs == 1));
      var self = this;
      setTimeout(function(){self.update();}, (1000));
    }
    function counterInit() { 
      var month = $("#d-month").html();
      var day = $("#d-day").html();
      var year = $("#d-year").html();
      var time = $("#d-time").html();
      new countDown( month + day + "," + year + time);
      // new countDown('May 9, 2015, 00:00:00', 'counter'); }
    }
    counterInit();
  }
});