date-helper-js

functions for working with date

Table of Contents

• Quick start
  • Install
  • Initialization
• Methods
  • getMonthNameByMonthIndex
  • getDayOfWeekNumber
  • getDayOfMonthNumber
  • getDateByDayOfMonthNumber
  • getNextMonth
  • getPrevMonth
  • getNextDay
  • getPrevDay
  • getFirstDateOfMonth
  • getLastDateOfMonth
  • isDatesEqual

Quick start

Install

We support all platforms.

npm

For module bundlers such as Webpack or Browserify.

npm i date-helper-js

Include with <script>

Download and install with script.

<script src="date-helper-js.js"></script>

CDN

Recommended for learning purposes, you can use the latest version:

<script src="https://cdn.jsdelivr.net/npm/date-helper-js/dist/lib/date-helper.js"></script>

Recommended for production for avoiding unexpected breakage from newer versions:

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/lib/date-helper.js"></script>

Initialization

ES6

date-helper-js as an ES6 module.

import { getMonthNameByMonthIndex } from 'date-helper-js';

getMonthNameByMonthIndex(1)

Node

date-helper-js as a Node.js module

const { getMonthNameByMonthIndex } = require('date-helper-js');

getMonthNameByMonthIndex(1)

Browser

Exports a global variable called dateHelper. Use it like this

Connect to html file <script src="https://cdn.jsdelivr.net/npm/date-helper-js/dist/lib/date-helper.js" ></script>

<script>
    dateHelper.getMonthNameByMonthIndex(1);
</script>

AMD

date-helper-js as an AMD module. Use with Require.js, System.js, and so on.

1. Download lib
2. Connect to your module loader

requirejs(['date-helper'], function(dateHelper) {
    dateHelper.getMonthNameByMonthIndex(1)
});

Methods

getMonthNameByMonthIndex

Return monthName by month index

Params

• monthIndex
  • Type: number
• arrayOfMonthNames
  • Type: Array.<string>

Returns

• string

Example

const monthIndex = 1
const monthNamesArray = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']
getMonthNameByMonthIndex(monthIndex, monthNamesArray)
// => 'February'

getDayOfWeekNumber

Return day of week number for selected date (0 - Sunday, 6 - Saturday)

Params

• date
  • Type: Date

Returns

• number

Example

getDayOfWeekNumber(new Date("2017-01-26")) //Thursday
// => 4

getDayOfMonthNumber

Return day of month number for selected date

Params

• date
  • Type: Date

Returns

• number

Example

getDayOfMonthNumber(new Date("2017-01-26")) //Thursday
// => 26

getDateByDayOfMonthNumber

Return Date by day of month number for selected date

Params

• monthDate
  • Type: Date
• dayOfMontNumber
  • Type: Date

Returns

• Date

Example

getDateByDayOfMonthNumber(new Date("2017-01-26"), 2)
// => new Date("2017-01-2")

getNextMonth

Return next month Date of selected date

Params

• date
  • Type: Date
  • Description: start date
• step
  • Type: number
  • Description: how many steps forward

Returns

• Date

Example

getNextMonth(new Date("2017-01-26"))
// => new Date("2017-02-26")

getNextMonth(new Date("2017-01-26"), 2)
// => new Date("2017-03-26")

getPrevMonth

Return prev month Date of selected date

Params

• date
  • Type: Date
  • Description: start date
• step
  • Type: number
  • Description: how many steps back

Returns

• Date

Example

getPrevMonth(new Date("2017-02-26"))
// => new Date("2017-01-26")

getPrevMonth(new Date("2017-03-26"), 2)
// => new Date("2017-01-26")

getNextDay

Return next day Date of selected date

Params

• date
  • Type: Date
  • Description: start date
• step
  • Type: number
  • Description: how many steps forward

Returns

• Date

Example

getNextDay(new Date("2017-01-26"))
// => new Date("2017-02-27")

getNextDay(new Date("2017-01-26"), 2)
// => new Date("2017-03-28")

getPrevDay

Return prev day Date of selected date

Params

• date
  • Type: Date
  • Description: start date
• step
  • Type: number
  • Description: how many steps back

Returns

• Date

Example

getPrevDay(new Date("2017-02-26"))
// => new Date("2017-01-25")

getPrevDay(new Date("2017-03-26"), 2)
// => new Date("2017-01-24")

getFirstDateOfMonth

Return first day of month from selected date

Params

• date
  • Type: Date

Returns

• Date

Example

getFirstDateOfMonth(new Date("2017-01-26"))
// => new Date("2017-01-01")

getLastDateOfMonth

Return last day of month from selected date

Params

• date
  • Type: Date

Returns

• Date

Example

getLastDateOfMonth(new Date("2017-01-26"))
// => new Date("2017-01-31")

isDatesEqual

Return result of comparing two dates

Params

• firstDate
  • Type: Date
• secondDate
  • Type: Date
• shouldCompareTime
  • Type: boolean

Returns

• Date

Example

isDatesEqual(new Date("2017-01-26"), new Date("2017-01-26"))
// => true

isDatesEqual(new Date("2017-01-26"), new Date("2017-01-27"))
// => false

isDatesEqual(new Date("2017-01-26 15:15:16"), new Date("2017-01-26 15:15:15"), true)
// => false

Author

webster6667