How to format time since xxx e.g. “4 minutes ago” similar to Stack Exchange sites

Question

The question is how to format a JavaScript Date as a string stating the time elapsed similar to the way you see times displayed on Stack Overflow.

e.g.<

Answer 1

This will show you past and previous time formats like '2 days ago' '10 minutes from now' and you can pass it either a Date object, a numeric timestamp or a date string

function time_ago(time) {

  switch (typeof time) {
    case 'number':
      break;
    case 'string':
      time = +new Date(time);
      break;
    case 'object':
      if (time.constructor === Date) time = time.getTime();
      break;
    default:
      time = +new Date();
  }
  var time_formats = [
    [60, 'seconds', 1], // 60
    [120, '1 minute ago', '1 minute from now'], // 60*2
    [3600, 'minutes', 60], // 60*60, 60
    [7200, '1 hour ago', '1 hour from now'], // 60*60*2
    [86400, 'hours', 3600], // 60*60*24, 60*60
    [172800, 'Yesterday', 'Tomorrow'], // 60*60*24*2
    [604800, 'days', 86400], // 60*60*24*7, 60*60*24
    [1209600, 'Last week', 'Next week'], // 60*60*24*7*4*2
    [2419200, 'weeks', 604800], // 60*60*24*7*4, 60*60*24*7
    [4838400, 'Last month', 'Next month'], // 60*60*24*7*4*2
    [29030400, 'months', 2419200], // 60*60*24*7*4*12, 60*60*24*7*4
    [58060800, 'Last year', 'Next year'], // 60*60*24*7*4*12*2
    [2903040000, 'years', 29030400], // 60*60*24*7*4*12*100, 60*60*24*7*4*12
    [5806080000, 'Last century', 'Next century'], // 60*60*24*7*4*12*100*2
    [58060800000, 'centuries', 2903040000] // 60*60*24*7*4*12*100*20, 60*60*24*7*4*12*100
  ];
  var seconds = (+new Date() - time) / 1000,
    token = 'ago',
    list_choice = 1;

  if (seconds == 0) {
    return 'Just now'
  }
  if (seconds < 0) {
    seconds = Math.abs(seconds);
    token = 'from now';
    list_choice = 2;
  }
  var i = 0,
    format;
  while (format = time_formats[i++])
    if (seconds < format[0]) {
      if (typeof format[2] == 'string')
        return format[list_choice];
      else
        return Math.floor(seconds / format[2]) + ' ' + format[1] + ' ' + token;
    }
  return time;
}

var aDay = 24 * 60 * 60 * 1000;
console.log(time_ago(new Date(Date.now() - aDay)));
console.log(time_ago(new Date(Date.now() - aDay * 2)));

Answer 2

function timeago(date) {
    var seconds = Math.floor((new Date() - date) / 1000);
    if(Math.round(seconds/(60*60*24*365.25)) >= 2) return Math.round(seconds/(60*60*24*365.25)) + " years ago";
    else if(Math.round(seconds/(60*60*24*365.25)) >= 1) return "1 year ago";
    else if(Math.round(seconds/(60*60*24*30.4)) >= 2) return Math.round(seconds/(60*60*24*30.4)) + " months ago";
    else if(Math.round(seconds/(60*60*24*30.4)) >= 1) return "1 month ago";
    else if(Math.round(seconds/(60*60*24*7)) >= 2) return Math.round(seconds/(60*60*24*7)) + " weeks ago";
    else if(Math.round(seconds/(60*60*24*7)) >= 1) return "1 week ago";
    else if(Math.round(seconds/(60*60*24)) >= 2) return Math.round(seconds/(60*60*24)) + " days ago";
    else if(Math.round(seconds/(60*60*24)) >= 1) return "1 day ago";
    else if(Math.round(seconds/(60*60)) >= 2) return Math.round(seconds/(60*60)) + " hours ago";
    else if(Math.round(seconds/(60*60)) >= 1) return "1 hour ago";
    else if(Math.round(seconds/60) >= 2) return Math.round(seconds/60) + " minutes ago";
    else if(Math.round(seconds/60) >= 1) return "1 minute ago";
    else if(seconds >= 2)return seconds + " seconds ago";
    else return seconds + "1 second ago";
}

Answer 3

My solution..

(function(global){
            const SECOND   = 1;
            const MINUTE   = 60;
            const HOUR     = 3600;
            const DAY      = 86400;
            const MONTH    = 2629746;
            const YEAR     = 31556952;
            const DECADE   = 315569520;

            global.timeAgo = function(date){
                var now = new Date();
                var diff = Math.round(( now - date ) / 1000);

                var unit = '';
                var num = 0;
                var plural = false;

                switch(true){
                    case diff <= 0:
                        return 'just now';
                    break;

                    case diff < MINUTE:
                        num = Math.round(diff / SECOND);
                        unit = 'sec';
                        plural = num > 1;
                    break;

                    case diff < HOUR:
                        num = Math.round(diff / MINUTE);
                        unit = 'min';
                        plural = num > 1;
                    break;

                    case diff < DAY:
                        num = Math.round(diff / HOUR);
                        unit = 'hour';
                        plural = num > 1;
                    break;

                    case diff < MONTH:
                        num = Math.round(diff / DAY);
                        unit = 'day';
                        plural = num > 1;
                    break;

                    case diff < YEAR:
                        num = Math.round(diff / MONTH);
                        unit = 'month';
                        plural = num > 1;
                    break;

                    case diff < DECADE:
                        num = Math.round(diff / YEAR);
                        unit = 'year';
                        plural = num > 1;
                    break;

                    default:
                        num = Math.round(diff / YEAR);
                        unit = 'year';
                        plural = num > 1;
                }

                var str = '';
                if(num){
                    str += `${num} `;
                }

                str += `${unit}`;

                if(plural){
                    str += 's';
                }

                str += ' ago';

                return str;
            }
        })(window);

        console.log(timeAgo(new Date()));
        console.log(timeAgo(new Date('Jun 03 2018 15:12:19 GMT+0300 (FLE Daylight Time)')));
        console.log(timeAgo(new Date('Jun 03 2018 13:12:19 GMT+0300 (FLE Daylight Time)')));
        console.log(timeAgo(new Date('May 28 2018 13:12:19 GMT+0300 (FLE Daylight Time)')));
        console.log(timeAgo(new Date('May 28 2017 13:12:19 GMT+0300 (FLE Daylight Time)')));
        console.log(timeAgo(new Date('May 28 2000 13:12:19 GMT+0300 (FLE Daylight Time)')));
        console.log(timeAgo(new Date('Sep 10 1994 13:12:19 GMT+0300 (FLE Daylight Time)')));

Answer 4

My stab at this based on other answers.

function timeSince(date) {
    let minute = 60;
    let hour   = minute * 60;
    let day    = hour   * 24;
    let month  = day    * 30;
    let year   = day    * 365;

    let suffix = ' ago';

    let elapsed = Math.floor((Date.now() - date) / 1000);

    if (elapsed < minute) {
        return 'just now';
    }

    // get an array in the form of [number, string]
    let a = elapsed < hour  && [Math.floor(elapsed / minute), 'minute'] ||
            elapsed < day   && [Math.floor(elapsed / hour), 'hour']     ||
            elapsed < month && [Math.floor(elapsed / day), 'day']       ||
            elapsed < year  && [Math.floor(elapsed / month), 'month']   ||
            [Math.floor(elapsed / year), 'year'];

    // pluralise and append suffix
    return a[0] + ' ' + a[1] + (a[0] === 1 ? '' : 's') + suffix;
}

Answer 5

I haven't checked (although it wouldn't be hard to), but I think that Stack Exchange sites use the jquery.timeago plugin to create these time strings.

---

It's quite easy to use the plugin, and it's clean and updates automatically.

Here's a quick sample (from the plugin's home page):

First, load jQuery and the plugin:

<script src="jquery.min.js" type="text/javascript"></script> <script src="jquery.timeago.js" type="text/javascript"></script>

Now, let's attach it to your timestamps on DOM ready:

jQuery(document).ready(function() {
jQuery("abbr.timeago").timeago(); });

This will turn all abbr elements with a class of timeago and an ISO 8601 timestamp in the title: <abbr class="timeago" title="2008-07-17T09:24:17Z">July 17, 2008</abbr> into something like this: <abbr class="timeago" title="July 17, 2008">about a year ago</abbr> which yields: about a year ago. As time passes, the timestamps will automatically update.

Answer 6

Here's what I did (the object returns the unit of time along with its value):

function timeSince(post_date, reference)
{
	var reference = reference ? new Date(reference) : new Date(),
		diff = reference - new Date(post_date + ' GMT-0000'),
		date = new Date(diff),
		object = { unit: null, value: null };
	
	if (diff < 86400000)
	{
		var secs  = date.getSeconds(),
			mins  = date.getMinutes(),
			hours = date.getHours(),
			array = [ ['second', secs], ['minute', mins], ['hour', hours] ];
	}
	else
	{
		var days   = date.getDate(),
			weeks  = Math.floor(days / 7),
			months = date.getMonth(),
			years  = date.getFullYear() - 1970,
			array  = [ ['day', days], ['week', weeks], ['month', months], ['year', years] ];
	}

	for (var i = 0; i < array.length; i++)
	{
		array[i][0] += array[i][1] != 1 ? 's' : '';

		object.unit  = array[i][1] >= 1 ? array[i][0] : object.unit;
		object.value = array[i][1] >= 1 ? array[i][1] : object.value;
	}

	return object;
}