javascriptdatedatetimegoogle-apps-scripthumanize

How to properly calculate remaining time in JS using getTime() from the two dates?


I'm trying to calculate remaining time (ex: 10 years, 2 months and 10 days from today(2014/03/02) in JS using this function:

var d2 = new Date(2024, 3, 12);
var d1 = new Date();
var d0 = new Date(1970, 0, 1);

var diff = new Date(d2.getTime() - (d1.getTime() + d0.getTime() ) );
var years = diff.getFullYear();
var months = diff.getMonth();
var days = diff.getDay();

alert("remaining time = " + years + " years, " + months + " months, " + days + " days.");

But instead of get the 10 years difference, I got 1980 years difference (though the days difference I understand that are produced buy the variation of days in months and years):

enter image description here

Is it possible to perform this "remaining time" operation using this strategy? If so, how to get the expected result?

Here the function in a JS shell: jsfiddle.net/3ra6c/


Solution

  • As I explained, Date is not equipped with such functions and you have to do the math yourself. You can get the milliseconds difference between two dates, but then it's down to doing the math to represent that as you wish.

    An example of using moment.js, loaded with require.js, with humanized approximations.

    Javascript

    require.config({
        paths: {
            moment: 'http://momentjs.com/downloads/moment.min'
        }
    });
    
    require(['moment'], function (moment) {
        var x = moment(new Date(2024, 3, 12)).from(new Date());
    
        console.log(x);
    });
    

    Output

    in 10 years
    

    On jsFiddle

    Look at their docs to see how you can humanize the output, you may want a little more detail.