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)')));

将上面的函数更改为

function timeSince(date) {

    var seconds = Math.floor(((new Date().getTime()/1000) - date)),
    interval = Math.floor(seconds / 31536000);

    if (interval > 1) return interval + "y";

    interval = Math.floor(seconds / 2592000);
    if (interval > 1) return interval + "m";

    interval = Math.floor(seconds / 86400);
    if (interval >= 1) return interval + "d";

    interval = Math.floor(seconds / 3600);
    if (interval >= 1) return interval + "h";

    interval = Math.floor(seconds / 60);
    if (interval > 1) return interval + "m ";

    return Math.floor(seconds) + "s";
}

否则它会显示“75分钟”(介于1到2小时之间)。它现在还假定输入日期是Unix时间戳。

Lokely使用的一个简短版本:

const intervals = [
  { label: 'year', seconds: 31536000 },
  { label: 'month', seconds: 2592000 },
  { label: 'day', seconds: 86400 },
  { label: 'hour', seconds: 3600 },
  { label: 'minute', seconds: 60 },
  { label: 'second', seconds: 1 }
];

function timeSince(date) {
  const seconds = Math.floor((Date.now() - date.getTime()) / 1000);
  const interval = intervals.find(i => i.seconds < seconds);
  const count = Math.floor(seconds / interval.seconds);
  return `${count} ${interval.label}${count !== 1 ? 's' : ''} ago`;
}

这应该正确地处理任何有效的时间戳，包括Date.now()、单数单位和未来日期。我漏掉了月份，但是这些月份应该很容易加进去。我尽量保持它的可读性。

function getTimeInterval(date) { let seconds = Math.floor((Date.now() - date) / 1000); let unit = "second"; let direction = "ago"; if (seconds < 0) { seconds = -seconds; direction = "from now"; } let value = seconds; if (seconds >= 31536000) { value = Math.floor(seconds / 31536000); unit = "year"; } else if (seconds >= 86400) { value = Math.floor(seconds / 86400); unit = "day"; } else if (seconds >= 3600) { value = Math.floor(seconds / 3600); unit = "hour"; } else if (seconds >= 60) { value = Math.floor(seconds / 60); unit = "minute"; } if (value != 1) unit = unit + "s"; return value + " " + unit + " " + direction; } console.log(getTimeInterval(Date.now())); // 0 seconds ago console.log(getTimeInterval(Date.now() + 1000)); // 1 second from now console.log(getTimeInterval(Date.now() - 1000)); // 1 second ago console.log(getTimeInterval(Date.now() + 60000)); // 1 minute from now console.log(getTimeInterval(Date.now() - 120000)); // 2 minutes ago console.log(getTimeInterval(Date.now() + 120000)); // 2 minutes from now console.log(getTimeInterval(Date.now() + 3600000)); // 1 hour from now console.log(getTimeInterval(Date.now() + 360000000000)); // 11 years from now console.log(getTimeInterval(0)); // 49 years ago

由@user1012181提供的ES6版本代码:

const epochs = [
    ['year', 31536000],
    ['month', 2592000],
    ['day', 86400],
    ['hour', 3600],
    ['minute', 60],
    ['second', 1]
];

const getDuration = (timeAgoInSeconds) => {
    for (let [name, seconds] of epochs) {
        const interval = Math.floor(timeAgoInSeconds / seconds);
        if (interval >= 1) {
            return {
                interval: interval,
                epoch: name
            };
        }
    }
};

const timeAgo = (date) => {
    const timeAgoInSeconds = Math.floor((new Date() - new Date(date)) / 1000);
    const {interval, epoch} = getDuration(timeAgoInSeconds);
    const suffix = interval === 1 ? '' : 's';
    return `${interval} ${epoch}${suffix} ago`;
};

由@ibe-vanmeenen编辑建议。(谢谢!)

简单易读版本:

const relativeTimePeriods = [
    [31536000, 'year'],
    [2419200, 'month'],
    [604800, 'week'],
    [86400, 'day'],
    [3600, 'hour'],
    [60, 'minute'],
    [1, 'second']
];

function relativeTime(date, isUtc=true) {
    if (!(date instanceof Date)) date = new Date(date * 1000);
    const seconds = (new Date() - date) / 1000;
    for (let [secondsPer, name] of relativeTimePeriods) {
        if (seconds >= secondsPer) {
            const amount = Math.floor(seconds / secondsPer);
            return `${amount} ${name}${amount ? 's' : ''}s ago`;
        }
    }
    return 'Just now';
}