README.md

plain-date

A simple, light-weight model for date handling in JavaScript

Module System

The package includes both an ESM module (browser-compatible) and CJS modules (npm-compatible).

plain-date is written in node-style and converted to ESM for wider distribution. The default is therefore the node variant.

CJS (node)

require('plain-date') gives you the PlainDate class. require('plain-date/calculation') gives you helper functions.

const PlainDate = require('plain-date')
const { startOfMonth, weekNumber } = require('plain-date/calculation')

ESM (browser)

index.mjs yields the PlainDate class as its default export and the helper functions as named exports.

import PlainDate, { startOfMonth, weekNumber } from 'plain-date'

API

Table of Contents

• PlainDate
  • Properties
  • Examples
  • getNativeDate
  • getComplexDate
  • toString
    • Parameters
  • valueOf
• PlainDate/3_parameters
  • Parameters
  • Examples
• PlainDate/2_parameters
  • Parameters
  • Examples
• PlainDate/1_parameter
  • Parameters
  • Examples
• daysBetween
  • Parameters
• startOfMonth
  • Parameters
• endOfMonth
  • Parameters
• startOfWeek
  • Parameters
• endOfWeek
  • Parameters
• weekNumber
  • Parameters

PlainDate

PlainDate objects represent calendar dates or months. They focus on ease of use and are very light in comparison with JavaScript's native Date type.

They have a small set of properties, are immutable, and every date can only ever exist once.

If you try to create a new PlainDate object with a date that has previously been created, you will receive that pre-existing PlainDate object.

Additionally, PlainDate objects can be intuitively compared.

PlainDate objects can be constructed with one to three parameters. Behaviour for unexpected inputs is not defined. In order to stay light-weight, there is no intelligent type checking.

Type: Object

Properties

• year number
• month number
• date number
• timestamp number

Examples

new PlainDate('2019-04-01') === new PlainDate('2019-04-01') // => true

new PlainDate('2019-04-01') < new PlainDate('2019-04-01') // => false

new PlainDate('2019-04-01') < new PlainDate('2019-04-11') // => true

new PlainDate('2019-04-01') > new PlainDate('2019-04-11') // => false

getNativeDate

Creates a new equivalent Date object. Multiple calls yield multiple distinct objects.

Returns Date

getComplexDate

Returns Date

Meta

• deprecated: Use getNativeDate instead

toString

Replaces each token in the given string by the appropriate string representation of the related data:

• YYYY: full year-number.
• YY: last two digits of year.
• MM: zero-padded two-digit month.
• DD: zero-padded two-digit date.

Defaults to the ISO format.

Parameters

• format string (optional, default 'YYYY-MM[-DD]')

Returns string

valueOf

Enables fast comparison via < and >.

Returns number

PlainDate/3_parameters

Parameters

• year (number | string)
• month (number | string)
• date (number | string)

Examples

new PlainDate(2019, 4, 1)

new PlainDate('2019', '04', '01')

PlainDate/2_parameters

Parameters

• year (number | string)
• month (number | string)

Examples

new PlainDate(2019, 4)

new PlainDate('2019', '4')

PlainDate/1_parameter

Parameters

• fullDate (string | Date | PlainDate | {year: number, month: number, date: number?})

Examples

new PlainDate('2019-04-01')

new PlainDate('2019-04')

new PlainDate(new Date(2019,3,1))

new PlainDate({
  year: 2019,
  month: 4,
})

daysBetween

Parameters

• one PlainDate
• other PlainDate

Returns number Difference between both dates, in days.

startOfMonth

Parameters

• given PlainDate

Returns PlainDate The first of the same month.

endOfMonth

Parameters

• given PlainDate

Returns PlainDate The last of the same month.

startOfWeek

Parameters

• given PlainDate
• firstDayIndex number

Returns PlainDate The first of the same week.

endOfWeek

Parameters

• given PlainDate
• firstDayIndex number

Returns PlainDate The last of the same week.

weekNumber

• See: https://stackoverflow.com/questions/6117814/get-week-of-year-in-javascript-like-in-php#6117889

Parameters

• given PlainDate

Returns number The number of the week within the current year, as per ISO 8601.