Use of date and time tools (dayjs)

Introduction

Day.js is a lightweight JavaScript library that handles time and date, which is exactly the same as the API design of Moment.js. If you have used Moment.js before, then you already know how to use Day.js

installation

npm install dayjs --save

import dayjs from 'dayjs'
// 或者 CommonJS
// var dayjs = require('dayjs');
dayjs().format()

API

DayjsJavascript does not change or override native Date.prototype, but to create a new containing Javascript Dateobjects Dayjsobjects.

DayjsObjects are immutable, all the operations of the API will return a new Dayjsobject.

Unless otherwise specified, Day.js return value is a new Dayjsobject.

Parsing

In dayjs()passing the supported formats

current time

Run directly dayjs()to obtain contains the current time and date Dayjsobjects.

dayjs()

Time string

It can parse a standard ISO 8601 time string passed in .

dayjs(String)
dayjs('1995-12-25')

Date object

A Javascript Date object passed in can be parsed.

dayjs(Date)
dayjs(new Date(2018, 8, 18))

Unix timestamp (milliseconds)

It can parse the incoming Unix timestamp (13 digits).

dayjs(Number)
dayjs(1318781876406)

Unix timestamp (seconds)

It can parse the incoming Unix timestamp (10 digits).

dayjs.unix(Number)
dayjs.unix(1318781876)

Custom time format

Parsing custom time formats such as dayjs("12-25-1995", "MM-DD-YYYY")may be used widgetCustomParseFormat

copy

DayjsObjects are immutable. If you want to get a copy of an object, please do .clone().
To dayjs()pass in a Dayjssubject can achieve the same effect.

dayjs(Dayjs)
dayjs().clone()

verification

return Boolean

The current detection Dayjswhether the object is a valid time.

dayjs().isValid()

Get + set

Get and change the date.

year

Get or set the year.

dayjs().year()
dayjs().year(2000)

month

Get or set the month. Start from 0

dayjs().month()
dayjs().month(0)

day

Get or set the date. Start from 1

dayjs().date()
dayjs().date(1)

week

Get or set the day of the week. Start on Sunday 0

dayjs().day()
dayjs().day(0)

Time

Get or set the hour.

dayjs().hour()
dayjs().hour(12)

Minute

Get or set the minutes.

dayjs().minute()
dayjs().minute(59)

second

Get or set seconds.

dayjs().second()
dayjs().second(1)

millisecond

Get or set milliseconds.

dayjs().millisecond()
dayjs().millisecond(1)

Obtain

Acquired from Dayjsthe information object to take
an incoming unit (unit) not case-sensitive.

dayjs().get(unit : String)
dayjs().get('month') // 从 0 开始
dayjs().get('day')

Available units

unit	abbreviation	description
`date`		date
`day`	`d`	Day of the week (Sunday 0, Saturday 6)
`month`	`M`	Month (January 0, December 11)
`year`	`y`	year
`hour`	`h`	Time
`minute`	`m`	Minute
`second`	`s`	second
`millisecond`	`ms`	millisecond

Set up

Set time

dayjs().set(unit : String, value : Int);
dayjs().set('date', 1);
dayjs().set('month', 3); // 四月
dayjs().set('second', 30);

operating

You can Dayjstarget the following operations increased to reduce the class:

dayjs()
  .startOf('month')
  .add(1, 'day')
  .subtract(1, 'year')

increase

Increase the time and returns a new Dayjs()object.

dayjs().add(value : Number, unit : String);
dayjs().add(7, 'day');

cut back

Reduce the time and returns a new Dayjs()object.

dayjs().subtract(value : Number, unit : String);
dayjs().subtract(7, 'year');

Start time

Returns the current time of the beginning of the time of Dayjs()an object, such as the first day of the month.

dayjs().startOf(unit : String);
dayjs().startOf('week'); // 取决于 locale 文件里 `weekStart` 的值

End time

Returns the current time to the end time of Dayjs()the object, such as the last day of the month.

dayjs().endOf(unit : String);
dayjs().endOf('month');

display

Formatting Dayjsobjects and display.

format

return String

Receive a series of time and date strings and replace them with corresponding values.

dayjs().format(String)
dayjs('2019-01-25').format('[YYYY] YYYY-MM-DDTHH:mm:ssZ[Z]') // 'YYYY 2019-01-25T00:00:00-02:00Z'
dayjs().format('{YYYY} MM-DDTHH:mm:ssZ[Z]') // "{2014} 09-08T08:02:17-05:00Z"

Details are as follows:

format	Output	description
`YY`	18	Two-digit year
`YYYY`	2018	Four-digit year
`M`	1-12	Month, starting from 1
`MM`	01-12	Month, two digits
`MMM`	Jan-Dec	Abbreviated month name
`MMMM`	January-December	Full month name
`D`	1-31	Day of the month
`DD`	01-31	Day of the month, two digits
`d`	0-6	Day of the week, Sunday is 0
`dd`	Drought	The shortest name of the day of the week
`ddd`	Sun-Sat	Abbreviated name of the day of the week
`dddd`	Sunday-Saturday	The name of the day of the week
`H`	0-23	hour
`HH`	00-23	Hour, two digits
`h`	1-12	Hour, 12 hour clock
`hh`	01-12	Hours, 12-hour clock, two digits
`m`	0-59	minute
`mm`	00-59	Minutes, two digits
`s`	0-59	second
`ss`	00-59	Two digits for seconds
`SSS`	000-999	Three digits in milliseconds
`Z`	+5:00	UTC offset
`ZZ`	+0500	UTC offset, prefix the number with 0
`A`	AM PM
`a`	am pm

More information about formatting options Q Do k kk X x ...you can use plug-insAdvancedFormat
本地化的长日期格式 L LT LTS ... 可以使用插件 LocalizedFormat

时间差

return Number

获取两个 Dayjs 对象的时间差，默认毫秒。

const date1 = dayjs('2019-01-25')
const date2 = dayjs('2018-06-05')
date1.diff(date2) // 20214000000
date1.diff(date2, 'month') // 7
date1.diff(date2, 'month', true) // 7.645161290322581
date1.diff(date2, 'day') // 233

Unix 时间戳 (毫秒)

return Number

返回 Unix 时间戳 (毫秒)

dayjs().valueOf()

Unix 时间戳 (秒)

return Number

返回 Unix 时间戳 (秒)。

dayjs().unix()

UTC 偏移量 (分)

返回 UTC 偏移量 (分)

dayjs().utcOffset()

天数 (月)

return Number

返回月份的天数。

dayjs().daysInMonth()

Date 对象

return Javascript Date object

返回原生的 Date 对象。

dayjs().toDate()

As JSON

return JSON String

当序列化 Dayjs 对象时，会返回 ISO8601 格式的字符串。

dayjs().toJSON() //"2018-08-08T00:00:00.000Z"

ISO 8601 字符串

return String

返回 ISO8601 格式的字符串。

dayjs().toISOString()

字符串

return String

dayjs().toString()

查询

是否之前

return Boolean

检查一个 Dayjs 对象是否在另一个 Dayjs 对象时间之前。

dayjs().isBefore(Dayjs, unit? : String);
dayjs().isBefore(dayjs()); // false
dayjs().isBefore(dayjs(), 'year'); // false

是否相同

return Boolean

检查一个 Dayjs 对象是否和另一个 Dayjs 对象时间相同。

dayjs().isSame(Dayjs, unit? : String);
dayjs().isSame(dayjs()); // true
dayjs().isSame(dayjs(), 'year'); // true

是否之后

return Boolean

检查一个 Dayjs 对象是否在另一个 Dayjs 对象时间之后。

dayjs().isAfter(Dayjs, unit? : String);
dayjs().isAfter(dayjs()); // false
dayjs().isAfter(dayjs(), 'year'); // false

是否是 Dayjs `.isDayjs(compared: any)`

返回一个 boolean 验证传入值是否是一个 Dayjs 对象.

dayjs.isDayjs(dayjs()) // true
dayjs.isDayjs(new Date()) // false

也可以使用 instanceof

dayjs() instanceof dayjs // true

UTC

如果想要使用 UTC 模式来解析和展示时间，.utc .local .isUTC 可以使用插件 UTC

插件 APIs

相对时间

.from .to .fromNow .toNow 获得相对时间

插件 RelativeTime

是否是闰年

.isLeapYear 获得是否闰年

插件 IsLeapYear

年中的第几周

.week 获取是第几个周

插件 WeekOfYear

星期

.weekday 来获取或设置当前语言的星期

plugin WeekDay

年中有几周 ISO

.isoWeeksInYear 获得年中有几周

plugin IsoWeeksInYear

是否相同或之后

.isSameOrAfter 返回一个时间和一个时间相同或在一个时间之后

插件 IsSameOrAfter

是否相同或之前

.isSameOrBefore 返回一个时间是否和一个时间相同或在一个时间之前

插件 IsSameOrBefore

是否之间

.isBetween 返回一个时间是否介于两个时间之间

插件 IsBetween

年中第几季度

.quarter 返回年中第几季度

插件 QuarterOfYear

转成数组

.toArray 返回包含时间数值的数组。

插件 ToArray

转成对象

.toObject 返回包含时间数值的对象

插件 ToObject

最小最大

.min .max 比较传入的 dayjs 实例的大小

plugin MinMax

日历时间

.calendar 来显示日历时间

plugin Calendar