日期工具

格式化持续时间

function formatDuration(ms) {
	if (ms < 0) ms = -ms;
	const time = {
		day: Math.floor(ms / 86400000),
		hour: Math.floor(ms / 3600000) % 24,
		minute: Math.floor(ms / 60000) % 60,
		second: Math.floor(ms / 1000) % 60,
		millisecond: Math.floor(ms) % 1000,
	};
	return Object.entries(time)
		.filter((val) => val[1] !== 0)
		.map(([key, val]) => `${val} ${key}${val !== 1 ? 's' : ''}`)
		.join(', ');
}

格式化秒

function formatSeconds(s) {
	const [hour, minute, second, sign] =
		s > 0
			? [s / 3600, (s / 60) % 60, s % 60, '']
			: [-s / 3600, (-s / 60) % 60, -s % 60, '-'];

	return (
		sign +
		[hour, minute, second]
			.map((v) => `${Math.floor(v)}`.padStart(2, '0'))
			.join(':')
	);
}

// 举个例子🌰
formatSeconds(200); // '00:03:20'
formatSeconds(-200); // '-00:03:20'
formatSeconds(99999); // '27:46:39'

计算两个日期之间的工作日

function countWeekDaysBetween(startDate, endDate) {
	return Array.from({
		length: (endDate - startDate) / (1000 * 3600 * 24),
	}).reduce((count) => {
		if (startDate.getDay() % 6 !== 0) count++;
		startDate = new Date(startDate.setDate(startDate.getDate() + 1));
		return count;
	}, 0);
}

// 举个例子🌰
countWeekDaysBetween(new Date('Oct 05, 2020'), new Date('Oct 06, 2020')); // 1
countWeekDaysBetween(new Date('Oct 05, 2020'), new Date('Oct 14, 2020')); // 7

日期添加工作日

function addWeekDays(startDate, count) {
	return Array.from({ length: count }).reduce((date) => {
		date = new Date(date.setDate(date.getDate() + 1));
		if (date.getDay() % 6 === 0)
			date = new Date(date.setDate(date.getDate() + (date.getDay() / 6 + 1)));
		return date;
	}, startDate);
}

// 举个例子🌰
addWeekDays(new Date('Oct 09, 2020'), 5); // 'Oct 16, 2020'
addWeekDays(new Date('Oct 12, 2020'), 5); // 'Oct 19, 2020'

日期新增分钟数

function addMinutesToDate(date, n) {
	const d = new Date(date);
	d.setTime(d.getTime() + n * 60000);
	return d.toISOString().split('.')[0].replace('T', ' ');
}

// 举个例子🌰
addMinutesToDate('2020-10-19 12:00:00', 10); // '2020-10-19 12:10:00'
addMinutesToDate('2020-10-19', -10); // '2020-10-18 23:50:00'

日期新增天数

function addDaysToDate() {
	const d = new Date(date);
	d.setDate(d.getDate() + n);
	return d.toISOString().split('T')[0];
}

// 举个例子🌰
addDaysToDate('2020-10-15', 10); // '2020-10-25'
addDaysToDate('2020-10-15', -10); // '2020-10-05'

生成日期范围

const dateRangeGenerator = function* (start, end, step = 1) {
  let d = start
  while (d < end) {
    yield new Date(d)
    d.setDate(d.getDate() + step)
  }
}

// 举个例子🌰
[...dateRangeGenerator(new Date('2021-06-01'), new Date('2021-06-04'))];// [ 2021-06-01, 2021-06-02, 2021-06-03 ]

校验日期是否合法

const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());

// 举个例子🌰
isDateValid('December 17, 1995 03:24:00'); // true
isDateValid('1995-12-17T03:24:00'); // true
isDateValid('1995-12-17 T03:24:00'); // false
isDateValid('Duck'); // false
isDateValid(1995, 11, 17); // true
isDateValid(1995, 11, 17, 'Duck

根据日期获取时间

const getColonTimeFromDate = (date) => date.toTimeString().slice(0, 8);

// 举个例子🌰
getColonTimeFromDate(new Date()); // '08:38:00'

根据日期获取季度和年份

function quarterOfYear(date = new Date()) {
	return [Math.ceil((date.getMonth() + 1) / 3), date.getFullYear()];
}

// 举个例子🌰
quarterOfYear(new Date('07/10/2018')); // [ 3, 2018 ]
quarterOfYear(); // [ 4, 2020 ]

根据日期获取星期几

const dayName = (date, locale) =>
	date.toLocaleDateString(locale, { weekday: 'long' });

// 举个例子🌰
dayName(new Date()); // 'Saturday'
dayName(new Date('09/23/2020'), 'de-DE'); // 'Samstag'

根据日期获取几天前的日期

function daysAgo(n, date) {
	let d = date || new Date();
	d.setDate(d.getDate() - Math.abs(n));
	return d.toISOString().split('T')[0];
}

// 举个例子🌰
daysAgo(20); // 2020-09-16 (if current date is 2020-10-06)

判断日期是否是 ISO 格式

function (val) {
  const d = new Date(val);
  return !Number.isNaN(d.valueOf()) && d.toISOString() === val;
}

// 举个例子🌰
isISOString('2020-10-12T10:10:10.000Z'); // true
isISOString('2020-10-12'); // false

获取给定日期的最大值

const maxDate = (...dates) => new Date(Math.max(...dates));

// 举个例子🌰
const dates = [
	new Date(2017, 4, 13),
	new Date(2018, 2, 12),
	new Date(2016, 0, 10),
	new Date(2016, 0, 9),
];
maxDate(...dates); // 2018-03-11T22:00:00.000Z

获取给定日期的最小值

const minDate = (...dates) => new Date(Math.min(...dates));

// 举个例子🌰
const dates = [
	new Date(2017, 4, 13),
	new Date(2018, 2, 12),
	new Date(2016, 0, 10),
	new Date(2016, 0, 9),
];
minDate(...dates); // 2016-01-08T22:00:00.000Z