relativeTimeRounding()

moment.relativeTimeRounding();  // getter
moment.relativeTimeRounding(fn);  // setter

duration.humanize 在将其提供给语言环境中指定的 relativeTime 格式字符串之前，会舍入一个可能为双精度的值。 要控制舍入，则可以使用 moment.relativeTimeRounding。

var roundingDefault = moment.relativeTimeRounding();

// 向下舍入相对时间。
moment.relativeTimeRounding(Math.floor);

moment.relativeTimeThreshold('s', 60);
moment.relativeTimeThreshold('m', 60);
moment.relativeTimeThreshold('h', 24);
moment.relativeTimeThreshold('d', 31);
moment.relativeTimeThreshold('M', 12);

var a = moment();
a.subtract({hours: 23, minutes: 59, seconds: 59});
a.toNow()  // == '23 小时内'  '向下舍入到最近的小时'

// 回退到默认值。
moment.relativeTimeRounding(roundingDefault);

甚至可以选择完全不舍入：

var retainValue = function (value) {
    return value;
};
moment.relativeTimeRounding(retainValue);

var a = moment();
a.subtract({hours: 39});
a.toNow() // == '1.625 天内', '向下舍入到最近的年份'

moment.relativeTimeRounding();  // getter
moment.relativeTimeRounding(fn);  // setter

duration.humanize rounds a possibly double value before supplying it to the relativeTime format string specified in the locale. To control the rounding you can use moment.relativeTimeRounding.

var roundingDefault = moment.relativeTimeRounding();

// Round relative time evaluation down
moment.relativeTimeRounding(Math.floor);

moment.relativeTimeThreshold('s', 60);
moment.relativeTimeThreshold('m', 60);
moment.relativeTimeThreshold('h', 24);
moment.relativeTimeThreshold('d', 31);
moment.relativeTimeThreshold('M', 12);

var a = moment();
a.subtract({hours: 23, minutes: 59, seconds: 59});
a.toNow()  // == 'in 23 hours'  'Round down towards the nearest hour'

// back to default
moment.relativeTimeRounding(roundingDefault);

You can even choose to do no rounding at all:

var retainValue = function (value) {
    return value;
};
moment.relativeTimeRounding(retainValue);

var a = moment();
a.subtract({hours: 39});
a.toNow() // == 'in 1.625 days', 'Round down towards the nearest year'