Can I see if a timer is still running?

Simple question here that I can't seem to find an answer for: Once a setTimeout is set, is there any way to see if it's still, well, set?

if (!Timer)
{
    Timer = setTimeout(DoThis,60000);
}

From what I can tell, when you clearTimeout, the variable remains at its last value. A console.log I just looked at shows Timer as being '12', no matter if the timeout has been set or cleared. Do I have to null out the variable as well, or use some other variable as a boolean saying, yes, I have set this timer? Surely there's a way to just check to see if the timeout is still running... right? I don't need to know how long is left, just if it's still running.

What I do is:

var timer = null;

if (timer != null) {
  window.clearTimeout(timer); 
  timer = null;
}
else {
  timer = window.setTimeout(yourFunction, 0);
}

There isn't anyway to interact with the timer except to start it or stop it. I typically null the timer variable in the timeout handler rather than use a flag to indicate that the timer isn't running. There's a nice description on W3Schools about how the timer works. In their example they use a flag variable.

The value you are seeing is a handle to the current timer, which is used when you clear (stop) it.

There is no need to check for an existing timer, just execute clearTimeout before starting the timer.

var timer;
//..
var startTimer = function() {
  clearTimeout(timer);
  timer = setTimeout(DoThis, 6000);
}

This will clear any timer before starting a new instance.

Set another variable Timer_Started = true with your timer. And also change the variable to false when the timer function is called:

// set 'Timer_Started' when you setTimeout
var Timer_Started = true;
var Timer = setTimeout(DoThis,60000);

function DoThis(){

   // function DoThis actions 
   //note that timer is done.
   Timer_Started = false;

}

function Check_If_My_Timer_Is_Done(){

   if(Timer_Started){
      alert("The timer must still be running.");
   }else{
      alert("The timer is DONE.");
   }

}

I usually nullify the timer:

var alarm = setTimeout(wakeUpOneHourLater, 3600000);
function wakeUpOneHourLater() {
    alarm = null;    //stop alarm after sleeping for exactly one hour
}
//...
if (!alarm) {
    console.log('Oops, waked up too early...Zzz...');
}
else {
    console.log('Slept for at least one hour!');
}

I know this is a necroposting but i think still people are looking for this.

This is what i use: 3 variables:

1. t for milliseconds since.. in Date Object for next target
2. timerSys for the actual interval
3. seconds threshold for milliseconds has been set

next i have a function timer with 1 variable the function checks if variable is truly, if so he check if timer is already running and if this is the case than fills the global vars , if not truly, falsely, clears the interval and set global var timerSys to false;

var t, timerSys, seconds;

function timer(s) {
  if (s && typeof s === "number") {
    if (typeof timerSys === "boolean" || typeof timerSys === "undefined") {
      timerSys = setInterval(function() {
        sys();
      }, s);
      t = new Date().setMilliseconds(s);
      seconds = s;
    }
  } else {
    clearInterval(timerSys);
    timerSys = false;
  }
  return ((!timerSys) ? "0" : t)
}

function sys() {
  t = new Date().setMilliseconds(seconds);

}

Example I

Now you can add a line to sys function:

function sys() {
  t = new Date().setMilliseconds(seconds);
  console.log("Next execution: " + new Date(t));
//this is also the place where you put functions & code needed to happen when interval is triggerd

}

And execute :

  timer(5000);

Every 5 seconds in console:

  //output:: Next execution: Sun May 08 2016 11:01:05 GMT+0200 (Romance (zomertijd))

Example II

function sys() {
  t = new Date().setMilliseconds(seconds);
  console.log("Next execution: " + seconds/1000 + " seconds");

}

$(function() {
  timer(5000);
});

Every 5 seconds in console:

      //output:: Next execution: 5 seconds

Example III

var t, timerSys, seconds;

function timer(s) {
  if (s && typeof s === "number") {
    if (typeof timerSys === "boolean" || typeof timerSys === "undefined") {
      timerSys = setInterval(function() {
        sys();
      }, s);
      t = new Date().setMilliseconds(s);
      seconds = s;
    }
  } else {
    clearInterval(timerSys);
    timerSys = false;
  }
  return ((!timerSys) ? "0" : t)
}

function sys() {
  t = new Date().setMilliseconds(seconds);
  console.log("Next execution: " + seconds / 1000 + " seconds");

}

$(function() {
  timer(5000);

  $("button").on("click", function() {
    $("span").text(t - new Date());
  })
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button>Freebeer</button>
<span></span>

Note this way you can go below 0