How to find out how much time has passed since the start of the timer?

Question

JavaScript

var timerId = setInterval(function() {
Startfnc();
}, 35000);

how to find out how much time has passed since the start of the timer?

so that the time would be displayed in this format: 2101

Answer 1

I think the decorator will help you
read the documentation on the topic here
UPDATE
in the node I execute the following js:

var time = new Date();
function Startfnc() {
  console.log('Startfnc exec now');
  time = new Date();
};

var timerId = setInterval(function () {
  Startfnc();
}, 10000);

var logging = setInterval(function () {
  var localdate = new Date();
  console.log('last coll: ' + (localdate - time));
}, 2000);

Result:
>node test
last coll: 2002
last coll: 4119
last coll: 6129
last coll: 8131
Startfnc exec now
last coll: 130
last coll: 2131
last coll: 4133
last coll: 6134
last coll: 8134
Startfnc exec now
last coll: 132
last coll: 2132
last coll: 4133
last coll: 6135
last coll: 8136
Startfnc exec now