Javascript Continue From a Specific Time - javascript

I have a timer and a time. The time format is like the currentTime variable in my code. I want to get the currentTime time and add +1 to it every second keeping the same time format. Also I would like to subtract the currentTime + 1 - the total hours but keeping it real time with setInterval. Hope I am clear about my questions. Thanks.
HTML
<button id="start">START</button>
<button id="pause">PAUSE</button>
<div id="output"></div>
Javscript
const startTimeButton = document.querySelector("#start")
const pauseTimeButton = document.querySelector("#pause")
const output = document.querySelector("#output");
let currentTime = "12: 42: 17";
let totalHours = 30;
let seconds = 0;
let interval = null;
const timer = () => {
seconds++;
// Get hours
let hours = Math.floor(seconds / 3600);
// Get minutes
let minutes = Math.floor((seconds - hours * 3600) / 60);
// Get seconds
let secs = Math.floor(seconds % 60);
if (hours < 10) {
hours = `0${hours}`;
}
if (minutes < 10) {
minutes = `0${minutes}`;
}
if (secs < 10) {
secs = `0${secs}`;
}
return `${hours}:${minutes}:${secs}`;
};
startTimeButton.addEventListener("click", () => {
pauseTimeButton.style.display = "flex";
startTimeButton.style.display = "none";
console.log("START TIME CLICKED");
if (interval) {
return;
}
interval = setInterval(timer, 1000);
});
pauseTimeButton.addEventListener("click", () => {
pauseTimeButton.style.display = "none";
startTimeButton.style.display = "flex";
console.log("PAUSE TIME CLICKED");
clearInterval(interval);
interval = null;
});
// Here is an example of what I would like to achive
// currentTime + 1 (each second)
// output.innerHTML = (parseInt(currentTime) + 1) - totalHours;

Related

How do I automatically restart the countdown timer after it reaches 0?

I am trying to find a way to restart my countdown timer at 2:00 again when it reaches 0:00. I don't know if I'm wrong, but it won't work.
const startingMinutes = 2;
let time = startingMinutes * 60;
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--;
time = time < 0 ? 0 : time;
if (time == 0) {
fn();
setInterval(updateCountdown, 1000)
return;
}
}
<p id="countdown">2:00</p>
Reset the time once it hits zero, and you don't need to call setInterval again. Also, by calling updateCountdown() directly we can avoid hardcoding 2:00 in the HTML.
const startingMinutes = 2;
let time = startingMinutes * 60;
const countdownEl = document.getElementById('countdown');
function updateCountdown(){
const minutes = Math.floor(time / 60);
let seconds = time % 60;
seconds = seconds < 10 ? '0' + seconds : seconds;
countdownEl.innerHTML = `${minutes}:${seconds}`;
time--;
time = time < 0 ? 0 : time;
if (time == 0) {
// fn(); <-- not sure what this is supposed to do, so I commented it out
time = startingMinutes * 60; // reset counter
}
}
setInterval(updateCountdown, 1000);
updateCountdown();
<p id="countdown"></p>
Just reset your time:
Sample
var startingMinutes = 2;
let time = startingMinutes * 60;
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--;
time = time < 0 ? 0 : time;
if (time == 0) {
fn();
time = startingMinutes * 60;
return;
}
function fn() {
console.log("timer reset");
}
}
<p id="countdown">2:00</p>
Slightly different methodology.
window.addEventListener('load', ticker(120, countdown('countdown')))
function countdown(target) {
let counter = document.getElementById(target)
return (now) => {
let minutes = Math.floor(now / 60)
let seconds = Math.round((now / 60) % 1 * 60)
seconds = seconds >= 0 && seconds < 10 ? seconds = '0'+seconds : seconds
counter.textContent = minutes+':'+seconds
}
}
function ticker(seconds, tick, step = 1000) {
let now = seconds;
(function next() {
tick(now)
now = now - 1 || seconds
setTimeout(next, step)
})()
}
<p id="countdown">Loading...</p>

Countdown It does not Work with click button

I have a simple question. I want to make this code work with the Reset time button when the time is start again from 30 min delete the ( You are Ready! ) and start the time
var seconds = 30;
function secondPassed() {
var minutes = Math.round((seconds - 30) / 60);
var remainingSeconds = seconds % 60;
if (remainingSeconds < 10) {
remainingSeconds = "0" + remainingSeconds;
}
document.getElementById('countdown').innerHTML = minutes + ":" + remainingSeconds;
if (seconds == 0) {
clearInterval(countdownTimer);
document.getElementById('countdown').innerHTML = "You are Ready!";
} else {
seconds--;
}
}
var countdownTimer = setInterval('secondPassed()', 1000);
<span id="countdown" class="timer">
Reset time
I created a new function to reset the seconds and restart the timer and linked it to the button. I have also isolated at the start of the js code the variables that will count the seconds and hold the reference to the Interval.
is this what you are looking for?
var seconds;
var countdownTimer;
function startTimer() {
if (!seconds || seconds == 0) {
seconds = 30;
clearInterval(countdownTimer);
countdownTimer = setInterval(secondPassed, 1000)
secondPassed();
}
}
function secondPassed() {
var minutes = Math.round((seconds - 30) / 60);
var remainingSeconds = seconds % 60;
if (remainingSeconds < 10) {
remainingSeconds = "0" + remainingSeconds;
}
document.getElementById('countdown').innerHTML = minutes + ":" + remainingSeconds;
if (seconds == 0) {
clearInterval(countdownTimer);
document.getElementById('countdown').innerHTML = "You are Ready!";
} else {
seconds--;
}
}
startTimer();
<html>
<body>
<div>
<span id="countdown" class="timer"></span>
</div>
Reset time
</body>
</html>
Here create a separate function where after clicking - it disables the button, sets the timer, and changes button text.
In secondPassed method, if seconds == 0, it enables the button, so that you can start count down again.
var seconds = 30;
var countdownTimer;
function secondPassed() {
var minutes = Math.round((seconds - 30) / 60);
var remainingSeconds = seconds % 60;
if (remainingSeconds < 10) {
remainingSeconds = "0" + remainingSeconds;
}
document.getElementById('countdown').innerHTML = minutes + ":" + remainingSeconds;
if (seconds == 0)
{
clearInterval(countdownTimer);
document.getElementById('reset').disabled = false;
document.getElementById('countdown').innerHTML = "You are Ready!";
} else
{
seconds--;
}
}
function start(){
seconds = 30;
document.getElementById('reset').innerHTML = "Reset";
document.getElementById('reset').disabled = true;
countdownTimer = setInterval('secondPassed()', 1000);
}
//on load call
start();
<div>
<span id="countdown" class="timer"/>
</div>
<button id="reset" onclick="start()">
Start
</button>
Let's assume something quite basic, like the following:
<div>00:00</div>
<button>Reset</button>
Below is an approach you could take, fully-commented.
// We'll start by getting a couple element references
const label = document.querySelector("div");
const button = document.querySelector("button");
// Next, we'll bind-up the click handler for the button
button.addEventListener("click", () => {
// When the user clicks the button, we'll set the time
// limit to 30 minutes and proceed
let timer = 60 * 30;
// Disable the button to prevent further clicks
button.disabled = true;
button.dataset.default = button.textContent;
button.textContent = "Now counting down!";
// Let's setup some code that will be executed every second
button.interval = setInterval(() => {
// This decimal will be a number like 29.9521
const decimal = timer / 60;
// We'll convert 29.9521 into 29, for 29 minutes
const wholeMinute = Math.floor(decimal);
// Next, we'll take the .9521 and multiply by 60 for seconds
const wholeSecond = Math.round(60 * (decimal - wholeMinute));
// We'll pad both of the numbers so they always have a leading 0
const lblMin = wholeMinute.toString().padStart(2, 0);
const lblSec = wholeSecond.toString().padStart(2, 0);
// As long as we aren't out of seconds
if (timer >= 0) {
// Reduce the timer by 1 second
timer = timer - 1;
// And print the new label on our label element
label.textContent = `${ lblMin }:${ lblSec }`;
// Then return, so we don't execute what comes next
return;
}
// If we made it this far, our timer ran out
// Start by enabling the button
button.disabled = false;
// Restore the original text of the button
button.textContent = button.dataset.default;
// And clear our interval, as it is no longer needed
clearInterval(button.interval);
// Our interval will 'tick' once every second (1000 milliseconds)
}, 1000);
});

How would I get this stopwatch to continue running after stop-starting instead of resetting to 00:00:00 upon stop-starting?

I have a stopwatch for a small tool here, I received most of the code from a previous question and I was going about trying to implement it, I began breaking it down and trying to understand it.
So far I think I understand most of it (Still some bits I am researching); however I was trying to adapt the code to my tool.
My requirements:
A start/stop button (a single button) - the value will change depending on if the timer is running or not.
A reset button - this will simply reset the timer to 00:00:00 and if the tool is running it will also stop it.
So far, the reset button is not configured, this is fine. The start and stop button works; however say I stopped the timer, and then started it again without resetting it, the timer just begins at 00:00:00 again, it will not continue from where it was paused.
It would be greatly appreciated if anyone would be able to explain how I could do this? I have tried the following:
Storing 'differenceInMillis for each loop of updateTimer() in a global variable, then subtracting the value from startTime = Date.now() each time the timer is restarted (This was suggested by a user in a previous question), I could not get this to work.
The code I have so far -
HTML (buttons and clock):
const outputElement = document.getElementById("outputt");
var startTime = 0;
var running = 0;
var splitcounter = 0;
function startstop() {
if (running == 0) {
running = 1;
startTime = Date.now();
startstopbutton.value = 'Stop';
document.getElementById("outputt").style.backgroundColor = "#2DB37B";
updateTimer();
} else {
running = 0;
// logTime();
startstopbutton.value = 'Start';
document.getElementById("outputt").style.backgroundColor = "#B3321B";
}
}
function updateTimer() {
if (running == 1) {
let differenceInMillis = Date.now() - startTime;
let {
hours,
minutes,
seconds
} = calculateTime(differenceInMillis);
let timeStr = `${pad(hours)}:${pad(minutes)}:${pad(seconds)}`;
outputElement.innerText = timeStr;
requestAnimationFrame(updateTimer);
}
}
function calculateTime(milliS) {
const SECONDS = 1000; // should be 1000 - only 10 to speed up the timer
const MINUTES = 60;
const HOURS = 60;
const RESET = 60;
let hours = Math.floor(milliS / SECONDS / MINUTES / HOURS);
let minutes = Math.floor(milliS / SECONDS / MINUTES) % RESET;
let seconds = Math.floor(milliS / SECONDS) % RESET;
return {
hours,
minutes,
seconds
};
}
function pad(time) {
return time.toString().padStart(2, '0');
}
<input id="startstopbutton" class="buttonZ" style="width: 120px;" type="button" name="btn" value="Start" onclick="startstop();">
<input id="resetbutton" class="buttonZ" style="width: 120px;" type="button" name="btnRst" id='btnRst' value="Reset" onclick="resetclock();" />
<div id="outputt" class="timerClock" value="00:00:00">00:00:00</div>
UPDATE new version - does not work however - session storage does not work at SO so will have to test elsewhere
const outputElement = document.getElementById("outputt");
var startTime = 0;
var running = 0;
var splitcounter = 0;
function startstop() {
if (running == 0) {
running = 1;
startTime = new Date(sessionStorage.getItem("time"))
if (isNaN(startTime)) startTime = Date.now();
startstopbutton.value = 'Stop';
document.getElementById("outputt").style.backgroundColor = "#2DB37B";
updateTimer();
} else {
running = 0;
logTime();
startstopbutton.value = 'Start';
document.getElementById("outputt").style.backgroundColor = "#B3321B";
}
}
function updateTimer() {
if (running == 1) {
let differenceInMillis = Date.now() - startTime;
sessionStorage.setItem("time", differenceInMillis)
let {
hours,
minutes,
seconds
} = calculateTime(differenceInMillis);
let timeStr = `${pad(hours)}:${pad(minutes)}:${pad(seconds)}`;
outputElement.innerText = timeStr;
requestAnimationFrame(updateTimer);
}
}
function calculateTime(milliS) {
const SECONDS = 1000; // should be 1000 - only 10 to speed up the timer
const MINUTES = 60;
const HOURS = 60;
const RESET = 60;
let hours = Math.floor(milliS / SECONDS / MINUTES / HOURS);
let minutes = Math.floor(milliS / SECONDS / MINUTES) % RESET;
let seconds = Math.floor(milliS / SECONDS) % RESET;
return {
hours,
minutes,
seconds
};
}
function pad(time) {
return time.toString().padStart(2, '0');
}
If you MUST use a date object, you will need to change
startTime = Date.now();
to
startTime = new Date(sessionStorage.getItem("time"))
if (isNaN(startTime)) startTime = Date.now();
and save the time
let differenceInMillis = Date.now() - startTime;
sessionStorage.setItem("time",differenceInMillis)
If not, use a counter instead of a date object
Also when you use a toggle as boolean, make it and use it as a boolean (good practice - not mandatory for this issue)
const outputElement = document.getElementById("outputt");
let counter = 0,
running = false,
splitcounter = 0,
lastTime = 0;
function startstop() {
running = !running;
startstopbutton.value = running ? 'Stop' : 'Start';
document.getElementById("outputt").style.backgroundColor = running ? "#2DB37B" : "#B3321B";
if (running) updateTimer(0)
}
function updateTimer(currentTime) {
if (running) requestAnimationFrame(updateTimer)
if (currentTime >= (lastTime + 1000)) {
counter++;
lastTime = currentTime;
let {
hours,
minutes,
seconds
} = calculateTime(counter * 1000);
let timeStr = `${pad(hours)}:${pad(minutes)}:${pad(seconds)}`;
outputElement.innerText = timeStr;
}
}
function calculateTime(milliS) {
const SECONDS = 1000; // should be 1000 - only 10 to speed up the timer
const MINUTES = 60;
const HOURS = 60;
const RESET = 60;
let hours = Math.floor(milliS / SECONDS / MINUTES / HOURS);
let minutes = Math.floor(milliS / SECONDS / MINUTES) % RESET;
let seconds = Math.floor(milliS / SECONDS) % RESET;
return {
hours,
minutes,
seconds
};
}
function pad(time) {
return time.toString().padStart(2, '0');
}
<input id="startstopbutton" class="buttonZ" style="width: 120px;" type="button" name="btn" value="Start" onclick="startstop();">
<input id="resetbutton" class="buttonZ" style="width: 120px;" type="button" name="btnRst" id='btnRst' value="Reset" onclick="resetclock();" />
<div id="outputt" class="timerClock" value="00:00:00">00:00:00</div>

How to save countup timer upon browser refresh?

I am new to stack overflow and javascript. My first task was to create a count up timer. My code works, but if the browser is refreshed I lose the timer spot. I've been reading on using local storage to save the spot, but I am not sure on how to add that into my current code. Anyone willing to lend a hand on this? This is what my current javascript looks like in my html file.
window.onload = () => {
let day = 0;
let hour = 0;
let minute = 0;
let seconds = 0;
let totalSeconds = 0;
let intervalId = null;
function startTimer() {
++totalSeconds;
day = Math.floor(totalSeconds/86400);
hour = Math.floor(totalSeconds /3600);
minute = Math.floor((totalSeconds - hour*3600)/60);
seconds = totalSeconds - (hour*3600 + minute*60);
document.getElementById("day").innerHTML = day;
document.getElementById("hour").innerHTML = hour;
document.getElementById("minute").innerHTML = minute;
document.getElementById("seconds").innerHTML = seconds;
}
document.getElementById('start-btn').addEventListener('click', () => {
intervalId = setInterval(startTimer, 1000);
})
document.getElementById('stop-btn').addEventListener('click', () => {
if (intervalId)
clearInterval(intervalId);
});
document.getElementById('reset-btn').addEventListener('click', () => {
totalSeconds = 0;
document.getElementById("day").innerHTML = '0';
document.getElementById("hour").innerHTML = '0';
document.getElementById("minute").innerHTML = '0';
document.getElementById("seconds").innerHTML = '0';
});
}
First of all, instead of storing the seconds elapsed, you should store when the timer started and then calculate the seconds elapsed.
Here, if the value for "start-timestamp" is present in the Local Storage, startTimestamp is set to it and the timer is activated.
When the timer is started, startTimestamp is set to the current time and stored in the Local Storage, and when it's stopped, "start-timestamp" is removed from the Local Storage.
let day = 0;
let hour = 0;
let minute = 0;
let seconds = 0;
let startTimestamp = 0;
let intervalId = null;
function updateTimer() {
let totalSeconds = (Date.now() - startTimestamp) / 1000;
day = Math.floor(totalSeconds/86400);
hour = Math.floor(totalSeconds /3600);
minute = Math.floor((totalSeconds - hour*3600)/60);
seconds = totalSeconds - (hour*3600 + minute*60);
document.getElementById("day").innerHTML = day;
document.getElementById("hour").innerHTML = hour;
document.getElementById("minute").innerHTML = minute;
document.getElementById("seconds").innerHTML = seconds;
}
{
const _startTimestamp = localStorage.getItem("start-timestamp");
if (_startTimestamp) {
startTimestamp = Number(_startTimestamp);
intervalId = setInterval(updateTimer, 1000);
}
}
document.getElementById('start-btn').addEventListener('click', () => {
if (!intervalId) {
startTimestamp = Date.now();
localStorage.setItem("start-timestamp", startTimestamp);
intervalId = setInterval(updateTimer, 1000);
}
})
document.getElementById('stop-btn').addEventListener('click', () => {
if (intervalId) {
clearInterval(intervalId);
localStorage.removeItem("start-timestamp");
}
});
document.getElementById('reset-btn').addEventListener('click', () => {
totalSeconds = 0;
document.getElementById("day").innerHTML = '0';
document.getElementById("hour").innerHTML = '0';
document.getElementById("minute").innerHTML = '0';
document.getElementById("seconds").innerHTML = '0';
});
For sessionStorage try the following to check if totalSeconds already set and a valid number .. set totalSeconds to what is stored in sessionStorage otherwise set to 0:
let tmpSession = parseInt(sessionStorage["totalSeconds"] ?? 0);
let totalSeconds = (isFinite(tmpSession))? tmpSession : 0;
Then in startTimer() after incrementing totalseconds write the value to sessionStorage, like so :
sessionStorage.setItem("totalSeconds",totalSeconds);

Countup since a specific date in javascript/jQuery [duplicate]

I want to use a simple countdown timer starting at 30 seconds from when the function is run and ending at 0. No milliseconds. How can it be coded?
var count=30;
var counter=setInterval(timer, 1000); //1000 will run it every 1 second
function timer()
{
count=count-1;
if (count <= 0)
{
clearInterval(counter);
//counter ended, do something here
return;
}
//Do code for showing the number of seconds here
}
To make the code for the timer appear in a paragraph (or anywhere else on the page), just put the line:
<span id="timer"></span>
where you want the seconds to appear. Then insert the following line in your timer() function, so it looks like this:
function timer()
{
count=count-1;
if (count <= 0)
{
clearInterval(counter);
return;
}
document.getElementById("timer").innerHTML=count + " secs"; // watch for spelling
}
I wrote this script some time ago:
Usage:
var myCounter = new Countdown({
seconds:5, // number of seconds to count down
onUpdateStatus: function(sec){console.log(sec);}, // callback for each second
onCounterEnd: function(){ alert('counter ended!');} // final action
});
myCounter.start();
function Countdown(options) {
var timer,
instance = this,
seconds = options.seconds || 10,
updateStatus = options.onUpdateStatus || function () {},
counterEnd = options.onCounterEnd || function () {};
function decrementCounter() {
updateStatus(seconds);
if (seconds === 0) {
counterEnd();
instance.stop();
}
seconds--;
}
this.start = function () {
clearInterval(timer);
timer = 0;
seconds = options.seconds;
timer = setInterval(decrementCounter, 1000);
};
this.stop = function () {
clearInterval(timer);
};
}
So far the answers seem to rely on code being run instantly. If you set a timer for 1000ms, it will actually be around 1008 instead.
Here is how you should do it:
function timer(time,update,complete) {
var start = new Date().getTime();
var interval = setInterval(function() {
var now = time-(new Date().getTime()-start);
if( now <= 0) {
clearInterval(interval);
complete();
}
else update(Math.floor(now/1000));
},100); // the smaller this number, the more accurate the timer will be
}
To use, call:
timer(
5000, // milliseconds
function(timeleft) { // called every step to update the visible countdown
document.getElementById('timer').innerHTML = timeleft+" second(s)";
},
function() { // what to do after
alert("Timer complete!");
}
);
Here is another one if anyone needs one for minutes and seconds:
var mins = 10; //Set the number of minutes you need
var secs = mins * 60;
var currentSeconds = 0;
var currentMinutes = 0;
/*
* The following line has been commented out due to a suggestion left in the comments. The line below it has not been tested.
* setTimeout('Decrement()',1000);
*/
setTimeout(Decrement,1000);
function Decrement() {
currentMinutes = Math.floor(secs / 60);
currentSeconds = secs % 60;
if(currentSeconds <= 9) currentSeconds = "0" + currentSeconds;
secs--;
document.getElementById("timerText").innerHTML = currentMinutes + ":" + currentSeconds; //Set the element id you need the time put into.
if(secs !== -1) setTimeout('Decrement()',1000);
}
// Javascript Countdown
// Version 1.01 6/7/07 (1/20/2000)
// by TDavid at http://www.tdscripts.com/
var now = new Date();
var theevent = new Date("Sep 29 2007 00:00:01");
var seconds = (theevent - now) / 1000;
var minutes = seconds / 60;
var hours = minutes / 60;
var days = hours / 24;
ID = window.setTimeout("update();", 1000);
function update() {
now = new Date();
seconds = (theevent - now) / 1000;
seconds = Math.round(seconds);
minutes = seconds / 60;
minutes = Math.round(minutes);
hours = minutes / 60;
hours = Math.round(hours);
days = hours / 24;
days = Math.round(days);
document.form1.days.value = days;
document.form1.hours.value = hours;
document.form1.minutes.value = minutes;
document.form1.seconds.value = seconds;
ID = window.setTimeout("update();", 1000);
}
<p><font face="Arial" size="3">Countdown To January 31, 2000, at 12:00: </font>
</p>
<form name="form1">
<p>Days
<input type="text" name="days" value="0" size="3">Hours
<input type="text" name="hours" value="0" size="4">Minutes
<input type="text" name="minutes" value="0" size="7">Seconds
<input type="text" name="seconds" value="0" size="7">
</p>
</form>
Just modified #ClickUpvote's answer:
You can use IIFE (Immediately Invoked Function Expression) and recursion to make it a little bit more easier:
var i = 5; //set the countdown
(function timer(){
if (--i < 0) return;
setTimeout(function(){
console.log(i + ' secs'); //do stuff here
timer();
}, 1000);
})();
var i = 5;
(function timer(){
if (--i < 0) return;
setTimeout(function(){
document.getElementsByTagName('h1')[0].innerHTML = i + ' secs';
timer();
}, 1000);
})();
<h1>5 secs</h1>
Expanding upon the accepted answer, your machine going to sleep, etc. may delay the timer from working. You can get a true time, at the cost of a little processing. This will give a true time left.
<span id="timer"></span>
<script>
var now = new Date();
var timeup = now.setSeconds(now.getSeconds() + 30);
//var timeup = now.setHours(now.getHours() + 1);
var counter = setInterval(timer, 1000);
function timer() {
now = new Date();
count = Math.round((timeup - now)/1000);
if (now > timeup) {
window.location = "/logout"; //or somethin'
clearInterval(counter);
return;
}
var seconds = Math.floor((count%60));
var minutes = Math.floor((count/60) % 60);
document.getElementById("timer").innerHTML = minutes + ":" + seconds;
}
</script>
For the sake of performances, we can now safely use requestAnimationFrame for fast looping, instead of setInterval/setTimeout.
When using setInterval/setTimeout, if a loop task is taking more time than the interval, the browser will simply extend the interval loop, to continue the full rendering. This is creating issues. After minutes of setInterval/setTimeout overload, this can freeze the tab, the browser or the whole computer.
Internet devices have a wide range of performances, so it's quite impossible to hardcode a fixed interval time in milliseconds!
Using the Date object, to compare the start Date Epoch and the current. This is way faster than everything else, the browser will take care of everything, at a steady 60FPS (1000 / 60 = 16.66ms by frame) -a quarter of an eye blink- and if the task in the loop is requiring more than that, the browser will drop some repaints.
This allow a margin before our eyes are noticing (Human = 24FPS => 1000 / 24 = 41.66ms by frame = fluid animation!)
https://caniuse.com/#search=requestAnimationFrame
/* Seconds to (STRING)HH:MM:SS.MS ------------------------*/
/* This time format is compatible with FFMPEG ------------*/
function secToTimer(sec){
const o = new Date(0), p = new Date(sec * 1000)
return new Date(p.getTime()-o.getTime()).toString().split(" ")[4] + "." + p.getMilliseconds()
}
/* Countdown loop ----------------------------------------*/
let job, origin = new Date().getTime()
const timer = () => {
job = requestAnimationFrame(timer)
OUT.textContent = secToTimer((new Date().getTime() - origin) / 1000)
}
/* Start looping -----------------------------------------*/
requestAnimationFrame(timer)
/* Stop looping ------------------------------------------*/
// cancelAnimationFrame(job)
/* Reset the start date ----------------------------------*/
// origin = new Date().getTime()
span {font-size:4rem}
<span id="OUT"></span>
<br>
<button onclick="origin = new Date().getTime()">RESET</button>
<button onclick="requestAnimationFrame(timer)">RESTART</button>
<button onclick="cancelAnimationFrame(job)">STOP</button>
You can do as follows with pure JS. You just need to provide the function with the number of seconds and it will do the rest.
var insertZero = n => n < 10 ? "0"+n : ""+n,
displayTime = n => n ? time.textContent = insertZero(~~(n/3600)%3600) + ":" +
insertZero(~~(n/60)%60) + ":" +
insertZero(n%60)
: time.textContent = "IGNITION..!",
countDownFrom = n => (displayTime(n), setTimeout(_ => n ? sid = countDownFrom(--n)
: displayTime(n), 1000)),
sid;
countDownFrom(3610);
setTimeout(_ => clearTimeout(sid),20005);
<div id="time"></div>
Based on the solution presented by #Layton Everson I developed a counter including hours, minutes and seconds:
var initialSecs = 86400;
var currentSecs = initialSecs;
setTimeout(decrement,1000);
function decrement() {
var displayedSecs = currentSecs % 60;
var displayedMin = Math.floor(currentSecs / 60) % 60;
var displayedHrs = Math.floor(currentSecs / 60 /60);
if(displayedMin <= 9) displayedMin = "0" + displayedMin;
if(displayedSecs <= 9) displayedSecs = "0" + displayedSecs;
currentSecs--;
document.getElementById("timerText").innerHTML = displayedHrs + ":" + displayedMin + ":" + displayedSecs;
if(currentSecs !== -1) setTimeout(decrement,1000);
}
// Javascript Countdown
// Version 1.01 6/7/07 (1/20/2000)
// by TDavid at http://www.tdscripts.com/
var now = new Date();
var theevent = new Date("Nov 13 2017 22:05:01");
var seconds = (theevent - now) / 1000;
var minutes = seconds / 60;
var hours = minutes / 60;
var days = hours / 24;
ID = window.setTimeout("update();", 1000);
function update() {
now = new Date();
seconds = (theevent - now) / 1000;
seconds = Math.round(seconds);
minutes = seconds / 60;
minutes = Math.round(minutes);
hours = minutes / 60;
hours = Math.round(hours);
days = hours / 24;
days = Math.round(days);
document.form1.days.value = days;
document.form1.hours.value = hours;
document.form1.minutes.value = minutes;
document.form1.seconds.value = seconds;
ID = window.setTimeout("update();", 1000);
}
<p><font face="Arial" size="3">Countdown To January 31, 2000, at 12:00: </font>
</p>
<form name="form1">
<p>Days
<input type="text" name="days" value="0" size="3">Hours
<input type="text" name="hours" value="0" size="4">Minutes
<input type="text" name="minutes" value="0" size="7">Seconds
<input type="text" name="seconds" value="0" size="7">
</p>
</form>
My solution works with MySQL date time formats and provides a callback function. on complition.
Disclaimer: works only with minutes and seconds, as this is what I needed.
jQuery.fn.countDownTimer = function(futureDate, callback){
if(!futureDate){
throw 'Invalid date!';
}
var currentTs = +new Date();
var futureDateTs = +new Date(futureDate);
if(futureDateTs <= currentTs){
throw 'Invalid date!';
}
var diff = Math.round((futureDateTs - currentTs) / 1000);
var that = this;
(function countdownLoop(){
// Get hours/minutes from timestamp
var m = Math.floor(diff % 3600 / 60);
var s = Math.floor(diff % 3600 % 60);
var text = zeroPad(m, 2) + ':' + zeroPad(s, 2);
$(that).text(text);
if(diff <= 0){
typeof callback === 'function' ? callback.call(that) : void(0);
return;
}
diff--;
setTimeout(countdownLoop, 1000);
})();
function zeroPad(num, places) {
var zero = places - num.toString().length + 1;
return Array(+(zero > 0 && zero)).join("0") + num;
}
}
// $('.heading').countDownTimer('2018-04-02 16:00:59', function(){ // on complete})
var hr = 0;
var min = 0;
var sec = 0;
var count = 0;
var flag = false;
function start(){
flag = true;
stopwatch();
}
function stop(){
flag = false;
}
function reset(){
flag = false;
hr = 0;
min = 0;
sec = 0;
count = 0;
document.getElementById("hr").innerHTML = "00";
document.getElementById("min").innerHTML = "00";
document.getElementById("sec").innerHTML = "00";
document.getElementById("count").innerHTML = "00";
}
function stopwatch(){
if(flag == true){
count = count + 1;
setTimeout( 'stopwatch()', 10);
if(count ==100){
count =0;
sec = sec +1;
}
}
if(sec ==60){
min = min +1 ;
sec = 0;
}
if(min == 60){
hr = hr +1 ;
min = 0;
sec = 0;
}
var hrs = hr;
var mins = min;
var secs = sec;
if(hr<10){
hrs ="0" + hr;
}
if(min<10){
mins ="0" + min;
}
if(sec<10){
secs ="0" + sec;
}
document.getElementById("hr").innerHTML = hrs;
document.getElementById("min").innerHTML = mins;
document.getElementById("sec").innerHTML = secs;
document.getElementById("count").innerHTML = count;
}

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