overlapping times javascripts html django

var timeList = [];

function addTime() {
  var startTime = document.getElementById("startTime").value;
  var endTime = document.getElementById("endTime").value;

  if (validate(startTime, endTime)){
    timeList.push({
      startTime: startTime,
      endTime: endTime
    });
    print(timeList);
    document.getElementById("error").innerHTML = "";
    }
  else
    document.getElementById("error").innerHTML = "Please select valid time";
}

function validate(sTime, eTime) {
  if (+getDate(sTime) < +getDate(eTime)) {
    var len = timeList.length;
    return len>0?(+getDate(timeList[len - 1].endTime) < +getDate(sTime) ):true;
  } else {
    return false;
  }
}

function getDate(time) {
  var today = new Date();
  var _t = time.split(":");
  today.setHours(_t[0], _t[1], 0, 0);
  return today;
}
function print(data){
  document.getElementById("content").innerHTML = "<pre>" + JSON.stringify(data, 0, 4) + "</pre>";
}<input type="text" id="startTime" />
<input type="text" id="endTime" />
<button onclick="addTime()">Add Time</button>
<p id="error"></p>

<div id="content"></div>