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How to get a timer to end on 0:00 in javascript

I have a timer that counts down from an amount of minutes which a user puts in but now I don't know how to get it to stop once the timer runs out
This is my javascript coding:
function getTime(){
const startingMinutes=prompt("How many minutes is your timer?");
let time=startingMinutes*60;
var overMin=0;
var overSec=00;
const countdownEl=document.getElementById("countdown");
setInterval(updateCountdown, 1000);
function updateCountdown(){
const minutes=Math.floor(time/60);
let seconds= time % 60;
seconds=seconds<10 ? '0' + seconds : seconds;
countdownEl.innerHTML= `${minutes}:${seconds}`;
time--;
if (minutes==0 && seconds==00){
document.getElementById('timesUp').play();
return;
}
}
}
What this ended up doing was playing the timer sound then the timer went backwards when I was trying to get it to stop.

setInterval() returns a timer ID. Use that to cancel it later with clearTimeout():
function getTime() {
const startingMinutes = prompt("How many minutes is your timer?");
let time = Number(startingMinutes) * 60 + 1;
const countdownEl = document.getElementById("countdown");
const timerId = setInterval(updateCountdown, 1000);
function updateCountdown() {
time--;
const minutes = Math.floor(time / 60);
let seconds = time % 60;
countdownEl.innerHTML = minutes + ':' + ('0' + seconds).slice(-2);
if(time <= 0) {
document.getElementById('timesUp').innerHTML = 'Done!';
clearTimeout(timerId);
}
}
}
getTime();
Count down: <span id="countdown"></span>
<div id="timesUp"></div>

Why does the counter created in javascript show different values?

There is a counter that counts down from 25. When I click on the link of the page, it continues to count from wherever it is left. So when I start at 25 and exit the page, it shows 15 when I come back 10 seconds later. But when I open it with a different browser, there is a different number, so the counter does not always show the same value. What could be the reason for this and what can I do?
var interval = 25000;
function reset() {
localStorage.endTime = +new Date() + interval;
}
if (!localStorage.endTime) {
reset();
}
function millisToMinutesAndSeconds(millis) {
var seconds = ((millis % 60000) / 1000).toFixed(0);
return (seconds < 10 ? "0" : "") + seconds;
}
setInterval(function () {
var remaining = localStorage.endTime - new Date();
if (remaining >= 0) {
document.getElementById("timer").innerText =
millisToMinutesAndSeconds(remaining);
} else {
reset();
}
}, 100);

Minutes not quite in sync with seconds

I have a timer which I am testing, it seems there is a bit of drift between when the minute countdown goes down by 1 and seconds whenever it reaches 59 seconds ()ie every minute:-
How can I alter this so they are both in sync?
my code is the following:-
$(document).ready(function() {
function now() {
return window.performance ? window.performance.now() : Date.now();
}
function tick() {
var timeRemaining = countdown - ((now() - initTick) / 1000);
timeRemaining = timeRemaining >= 0 ? timeRemaining : 0;
var countdownMinutes = Math.floor(timeRemaining / 60);
var countdownSeconds = timeRemaining.toFixed() % 60;
countdownTimer.innerHTML = countdownMinutes + ":" + countdownSeconds;
if (countdownSeconds < 10) {
countdownTimer.innerHTML = countdownMinutes + ":" + 0 + countdownSeconds;
}
if (timeRemaining > 0) {
setTimeout(tick, delay);
}
}
var countdown = 600; // time in seconds until user may login again
var delay = 20; // time (in ms) per tick
var initTick = now(); // timestamp (in ms) when script is initialized
var countdownTimer = document.querySelector(".timer"); // element to have countdown written to
setTimeout(tick, delay);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="timer"></div>
js fiddle: https://jsfiddle.net/robbiemcmullen/cer8qemt/1/

The issue is the precision is not the same for minutes and seconds.
You need to round to the nearest second before /60 / %60.
Consider: exactly 9 mins remaining:
var x = 540;
console.log(x.toFixed() % 60, Math.floor(x / 60));`
Output is: (0,9)
Then consider the call 20 ms later:
var x = 539.980;
console.log(x.toFixed() % 60, Math.floor(x / 60));
the output is now: (0, 8).
So the seconds haven't changed (yet) but the minute does.

Here is a version using setInterval and removing the use of .toFixed ()
Why do you use an interval of 20ms and not 1 second?
//method for countdown timer
$(document).ready(function() {
function now() {
return window.performance ? window.performance.now() : Date.now();
}
function tick() {
var timeRemaining = countdown - elapsedTime;
var countdownMinutes = Math.floor(timeRemaining / 60);
var countdownSeconds = timeRemaining % 60;
countdownTimer.innerHTML = countdownMinutes + ":" + countdownSeconds;
if (countdownSeconds < 10) {
countdownTimer.innerHTML = countdownMinutes + ":" + 0 + countdownSeconds;
}
++elapsedTime;
return timeRemaining;
}
var countdown = 600;
var elapsedTime = 0;
var timeRemaining;
// countdown: time in seconds until user may login again
//var delay = 20;
// delay: time (in ms) per tick
var initTick = now(); // initTick: timestamp (in ms) when script is initialized
var countdownTimer = document.querySelector(".timer");
// countdownTimer: element to have countdown written to
var interval = setInterval(function() {
if(tick() <= 0) {
clearInterval(interval);
}
}, 1000);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="timer"></div>
js fiddle https://jsfiddle.net/ud3wm8t1/

javascript timer keeps reseting too soon (not working)

// This timer keeps reseting back to 2:00 after it reaches 1 minute. Also i do not get a notification that says times up at the right time. Can someone please correct the code. Also the stop/resume timer button also has to stay functional.
var isRunning = false;
var ticker; //this will hold our setTimeout
var seconds,
minutes;
function countdown(mins, secs) {
//i made these global, so we can restart the timer later
seconds = secs || 60; //if user put in a number of minutes, use that. Otherwise, use 60
minutes = mins;
console.log('time stuff',mins,secs,minutes,seconds)
function tick() {
var counter = document.getElementById("timer");
var current_minutes = mins - 1
seconds--;
counter.innerHTML =
current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
if (seconds < 1 && minutes) {
//seconds reached 0, and still minutes left;
seconds=60;
minutes--;
}
if ((seconds > 0 || minutes > 0) && isRunning) {
ticker = setTimeout(tick, 1000);
} else if(isRunning){
console.log(seconds,minutes,isRunning)
alert('Time\'s up, brah!')
}
}
tick();
}
function timeToggle() {
isRunning = !isRunning; //if it's false, set it true. If it's true, set it false.
if (!isRunning) {
clearTimeout(ticker); //or whatever else you set the initial timeOut to.
} else {
//not running! and time is defined;
var sec = seconds||60;
console.log('def!',minutes, sec)
countdown(minutes, sec);
}
}
isRunning = true;
countdown(2);
<div id="timer">2:00</div>
<button onclick="timeToggle()">Stop time</button>

There is a small flaw in your logic.
During the countdown initialization your doing
seconds = secs || 60;
Which effectively add 60 seconds to the time you want if you don't initialize the seconds. see:
function countdownInit(mins, secs) {
seconds = secs || 60;
minutes = mins;
console.log(mins + 'min ' + seconds + 'sec');
}
countdownInit(1, 30) // ok
// 1min 30sec
countdownInit(1) // not ok
// 1min 60sec
// thats 2 minutes
The second issue here is that you use a var current_minutes that equals minutes - 1 to display the time. So you are not showing the real counter.
the fix is as follow:
function countdown(mins, secs) {
seconds = secs;
minutes = mins;
// if secs is 0 or uninitialized we set seconds to 60 and decrement the minutes
if(!secs) {
minutes--;
seconds = 60;
}
function tick() {
var counter = document.getElementById("timer");
seconds--;
// we use minutes instead of current_minutes in order to show what's really in our variables
counter.innerHTML =
minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
// rest of code
}
// rest of code
}
I tried to keep as much as your code as possible.

How to initialize a countdown timer to reflect the user input

I'm creating a countdown timer based on a users input. When the user pauses and resumes, the timer restarts at the initial inputed value and fails to resume from the current interval. I've uploaded the code into Codepen.
http://codepen.io/alivera/pen/JGpvRx
//Timer
var myTimer;
var duration = sessionCounter * 60;
var startTimer = function() {
minutes = parseInt(duration / 60);
seconds = parseInt(duration % 60);
minutes = minutes < 10 ? "0" + minutes : minutes;
seconds = seconds < 10 ? "0" + seconds : seconds;
document.getElementById("clockTimer").innerHTML = minutes + ":" + seconds;
if (--duration < 0) {
document.getElementById("toggleStatus").innerHTML = "<br>Break!";
}
};
//Start Timer
var go = function() {
myTimer = setInterval(startTimer, 1000);
document.getElementById('start').innerHTML = "Stop";
document.getElementById('start').className = "btn btn-danger";
document.getElementById("start").onclick = stop;
};
//Stop Timer
var stop = function() {
clearInterval(myTimer);
document.getElementById('start').innerHTML = "Start";
document.getElementById('start').className = "btn btn-success";
document.getElementById("start").onclick = go;
};
duration.onload = stop();

You're loading the time to count down from from the #clockTimer element:
var sessionCounter = document.getElementById("clockTimer").innerHTML;
This is bad because the contents of that element are changing. Often.
And parseInt on the next line only is only giving you the number before the colon. Your best bet for solving this problem would be storing the current time remaining and the previously set time in separate variables, as I have done below.
Your code was a little difficult to work with, so while correcting the error(s), I ended up almost completely rewriting it.
Here's my version; I'll explain it line-by-line (or section-by-section, or whatever):
First, put all of our elements in to easy-to-use (and type) variables:
var subBreakButton = document.getElementById("subBreakButton"),
breakTimer = document.getElementById("breakTimer"),
addBreakButton = document.getElementById("addBreakButton"),
subSessionButton = document.getElementById("subSessionButton"),
sessionTimer = document.getElementById("sessionTimer"),
addSessionButton = document.getElementById("addSessionButton"),
breakSession = document.getElementById("breakSession"),
clockTimer = document.getElementById("clockTimer"),
These variables are in seconds (thus m * s):
breakLength = 5 * 60, // Minutes to seconds
sessionLength = 25 * 60, // Minutes to seconds
sessionTimeLeft = sessionLength;
Next, a helper method that formats times into a mm:ss ... format:
function timeString (seconds) {
var minutes = parseInt(seconds / 60) + "",
seconds = parseInt(seconds % 60) + "";
if (minutes.length === 1)
minutes = "0" + minutes;
if (seconds.length === 1)
seconds = "0" + seconds;
return minutes + ":" + seconds;
}
Third, event listeners for the plus and minus buttons:
// Event Listeners
addBreakButton.addEventListener("click", function () {
breakLength += 1 * 60;
breakTimer.innerHTML = timeString(breakLength);
});
subBreakButton.addEventListener("click", function () {
breakLength -= 1 * 60;
if (breakLength < 0)
breakLength = 0;
breakTimer.innerHTML = timeString(breakLength);
});
addSessionButton.addEventListener("click", function () {
sessionLength += 1 * 60;
sessionTimer.innerHTML = timeString(sessionLength);
});
subSessionButton.addEventListener("click", function () {
sessionLength -= 1 * 60;
if (sessionLength < 0)
sessionLength = 0;
sessionTimer.innerHTML = timeString(sessionLength);
});
And, the fun part:
// Timer
var myTimer;
function startTimer () {
if (myTimer) // Check to see if a timer was already running, and if so, stop it
stopTimer();
sessionTimeLeft = sessionLength;
myTimer = setInterval(function () {
sessionTimeLeft--;
if (sessionTimeLeft <= 0) {
sessionTimeLeft = 0;
stopTimer();
}
clockTimer.innerHTML = (sessionTimeLeft <= 0? "Break!": timeString(sessionTimeLeft));
}, 1000);
}
function stopTimer () {
clearInterval(myTimer);
myTimer = 0;
}
Lastly, wrappers:
// Start Timer
function go() {
startTimer();
}
//Pause Timer
function stop() {
stopTimer();
}
Codepen: http://codepen.io/anon/pen/ZQjLZE?editors=1010