Doubt Javascript Date () [front-end]

Question

Doubt Javascript Date () [front-end]

Navigation

#1 by (3 votes)

0

I'm building a personal blog using GitHub Pages and a desktop app with NWJS to do the back end administration however I have a big question when presenting dates on the front end.

Because this is a "static" site, the posts are markdown files and their configuration files json , in the desktop application use moment .js to save the timestamp of the publication (or edition) but I do not know the best approach (or method) to deal with the user's timezone since the javascript function is responsible for showing how much time has been spent the publication (edit) depends on the user's timezone.

When making a publication the timestamp is based on my computer's time (or custom setting moment.js) bad users from a different timezone received different times on the front end based on their own times.

I'm not sure how to proceed to resolve this? Thanks for any help or referral links.

function.js

/**
 * Time ago (UNIX)
 * @param {string|number} time
 * @return {string} human readable time elapsed
 */
function timeAgo(time){
    var round = Math.round,
        now = new Date,
        t;
    //
    let format = function(n, unit){
        let a = 'hour' == unit ? 'an' : '1';
        unit = 1 == n ? unit : (unit !== 'month' ? unit + 's' : unit);
        return (1 == n ? a : n) + ' ' + unit;
    };
    // past / future
    let diff = (time > now) ? (time - now) : (now - time);
    // just now
    if (1e3 > diff) return 'now';
    // s, m, h, d, w, m, y
    if (60 > (t = round(diff / 1e3))) return format(t, 'second');
    if (60 > (t = round(diff / 6e4))) return format(t, 'minute');
    if (24 > (t = round(diff / 3.6e+6))) return format(t, 'hour');
    if (7 > (t = round(diff / 8.64e+7))) return format(t, 'day');
    if (4.34812 > (t = diff / 6.048e+8)) return format(round(t), 'week');
    if (12 > (t = round(diff / 2.63e+9))) return format(t, 'month');
    if (10 > (t = round(diff / 3.156e+10))) return format(t, 'year');
    // decades
    return format(round(diff / 3.156e+11), 'decade');
};

let btn = document.getElementById('click');
btn.addEventListener('click', function(ev){
    ev.preventDefault();
    let now = timeAgo(1502085380495);
    let span = document.getElementById('show');
    span.innerHTML = 'Published there ' + now;
}, false);

<button id="click">click to example</button>
<br>
<br>
<span id="show"></span>

javascript date timestamp front-end momentjs

asked by anonymous 07.08.2017 / 08:24

1 answer

Sum of days on a date Where can I use GUI with .NET Core?

score 3 · Accepted Answer

The best option to handle this is to store the date in UTC. According to the moment documentation, unless you set a timezone, the date is always created at the local timezone:

Unless you specify a time zone offset, parsing the string will create a date in the current time zone - Moment Docs

In this way, storing the date in UTC, when you parsing the date on the client, it will be correctly converted to the local timezone. Example:

Storing (backend or frontend):

//Armazena a data como String - 2017-08-07T07:34:49Z
let timestamp = moment.utc().format();

Date display in frontend:

//Realiza o parsing - 2017-08-07T04:34:49-03:00
let full_timestamp = moment("2017-08-07T07:34:49Z").format();

//07-08-2017 04:34
let formatted = moment("2017-08-07T07:34:49Z").format("DD-MM-YY HH:mm");