How do I calculate a duration time?

问题

I am developing a web-based application to capture start time and end time from system date-time but my main problem is that I don't know how can I get the duration time, between start and end time for downtime.

 //Function to get current start time
  var startTime = setInterval(function () { start() }, 1000);

  function start() {
    var startDate = new Date();
    var timeStart = startDate.toLocaleTimeString();
  $("#setCount").html(timeStart);
 }

回答1:

Do you mean this:

var date1 = new Date();
var date2 = new Date();
var diff = date2 - date1; //milliseconds interval

upd

check JSFiddle

回答2:

Update:

If you want to display the time difference to user, Serigo's method will do it. But if it is for any development purposes, below functions will make your life easy.

---

Just wanted to let you know about this console utility functions.

Put this line in top of your app initialization code console.time('appLifeTime');

Put this one in where ever you feel that your app ends. console.timeEnd('appLifeTime');

console.time('appLifeTime');

setTimeout(function delay(){
  console.timeEnd('appLifeTime');
}, 1500);

The above code piece will print, appLifeTime: 1500.583ms.

AFAIK, console.time & console.timeEnd works in firefox(with firebug) & webkit browsers(chrome, safari).

回答3:

To simply measure time elapsed, use Date.getTime() which outputs current time in milliseconds since unix epoch.

You can substract one millis value from another to get the duration.

Example:

var startTime = new Date().getTime();

setTimeout(function () {
  var endTime = new Date().getTime();
  console.log("duration [ms] = " + (endTime-startTime));
}, 1500);

Output would be, of course: duration [ms] = 1500 (or couple ms less or more).

回答4:

I have this function to show the time distance between two dates:

export const timeDistance = (date1, date2) => {
  let distance = Math.abs(date1 - date2);
  const hours = Math.floor(distance / 3600000);
  distance -= hours * 3600000;
  const minutes = Math.floor(distance / 60000);
  distance -= minutes * 60000;
  const seconds = Math.floor(distance / 1000);
  return `${hours}:${('0' + minutes).slice(-2)}:${('0' + seconds).slice(-2)}`;
};

The output in the format h:mm:ss hours can grow arbitrary.

回答5:

Use this nifty jQuery plugin: http://timeago.yarp.com/

Timeago is a jQuery plugin that makes it easy to support automatically updating fuzzy timestamps (e.g. "4 minutes ago" or "about 1 day ago"). Download, view the examples, and enjoy.

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来源：https://stackoverflow.com/questions/15493521/how-do-i-calculate-a-duration-time