我修改了Sky Sanders的版本。Math.floor(…)操作在if块中计算

       var timeSince = function(date) {
            var seconds = Math.floor((new Date() - date) / 1000);
            var months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
            if (seconds < 5){
                return "just now";
            }else if (seconds < 60){
                return seconds + " seconds ago";
            }
            else if (seconds < 3600) {
                minutes = Math.floor(seconds/60)
                if(minutes > 1)
                    return minutes + " minutes ago";
                else
                    return "1 minute ago";
            }
            else if (seconds < 86400) {
                hours = Math.floor(seconds/3600)
                if(hours > 1)
                    return hours + " hours ago";
                else
                    return "1 hour ago";
            }
            //2 days and no more
            else if (seconds < 172800) {
                days = Math.floor(seconds/86400)
                if(days > 1)
                    return days + " days ago";
                else
                    return "1 day ago";
            }
            else{

                //return new Date(time).toLocaleDateString();
                return date.getDate().toString() + " " + months[date.getMonth()] + ", " + date.getFullYear();
            }
        }

也可以使用dayjs的relativeTime插件来解决这个问题。

import * as dayjs from 'dayjs';
import * as relativeTime from 'dayjs/plugin/relativeTime';

dayjs.extend(relativeTime);
dayjs(dayjs('1990')).fromNow(); // x years ago

我的尝试是基于其他的答案。

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;
}

我一直在寻找这个问题的答案，并且几乎实现了其中一个解决方案，但一位同事提醒我检查react-intl库，因为我们已经在使用它了。

所以在解决方案中…在使用react-intl库的情况下，它们有一个<FormattedRelative>组件。

https://github.com/yahoo/react-intl/wiki/Components#formattedrelative

在这种情况下可能有点过头了，但如果有机会，moment.js真的很棒!

js是一个javascript datetime库，在这种情况下使用它，你需要做:

moment(yourdate).fromNow()

http://momentjs.com/docs/#/displaying/fromnow/

2018附录:Luxon是一个新的现代图书馆，可能值得一看!

2022年附录:Day.js是一个较新的库，比Luxon轻80%左右，具有类似的功能。

我的解决方案。

(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)')));