Create a date formatter with given format.

Usage no npm install needed!

<script type="module">
  import favTypeFormatDate from 'https://cdn.skypack.dev/@fav/type.format-date';


@fav/type.format-date NPM version MIT License Build Status Build Status Coverage status

Converts a date to a string in various date formats.

"fav" is an abbreviation of "favorite" and also the acronym of "for all versions". This package is intended to support all Node.js versions and many browsers as possible. At least, this package supports Node.js >= v0.10 and major Web browsers: Chrome, Firefox, IE11, Edge, Vivaldi and Safari.


To install from npm:

$ npm install --save @fav/type.format-date

NOTE: npm < 2.7.0 does not support scoped package, but old version Node.js supports it. So when you use such older npm, you should download this package from github.com, and move it in node_modules/@fav/type.format-date/ directory manually.


For Node.js:

var formatDate = require('@fav/type.format-date');
var formatMMDD = formatDate('MM/DD');
formatMMDD(new Date(2017, 10, 5)); // => '11/05'

var formatCustom = formatDate('YYYY/MM/DD (Week)', {
  Week: function(date) {
    return ['日', '月', '火', '水', '木', '金', '土'][date.getDay()]
formatCustom(new Date(2018, 4, 30)); // => '2018/05/30 (水)'

For Web browsers:

<script src="fav.type.format-date.min.js"></script>
var formatDate = fav.type.formatDate;
var formatMMDD = formatDate('MM/DD');
formatMMDD(new Date(2017, 10, 5)); // => '11/05'


formatDate(format [, opts]) : function

Creates a date format function which convert a date to a string in the specified format.

Conversion of each element field in format can be customized with the parameter opts, which is a plain object of which keys are field characters and of which values are converting functions.


Parameter Type Description
format string A date format string, which consists of the following date element fields.
opts object A plain object having pairs of a field character and a converting function.
Date element fields:
Character Description Example
'Y'* Full year. 'YYYY' => '2017'
'y'* Year of century (0〜±99). 'yy' => '17'
'M'* Month (1〜12) 'MM' => '11'
'Mmm' Month abbreviation 'Mmm' => 'Nov'
'Month' Month full name 'Month' => 'November'
'D'* Day of month (1〜31) 'DD' => '05'
'H'* Hours (0〜23) 'HH' => '14'
'm'* Minutes (0〜59) 'mm' => '45'
's'* Seconds (0〜59) 'ss' => '06'
'S'* Hours (0〜59) 'SSS' => '023'
'Www' Week abbreviation 'Www' => 'Sun'
'Week' Week full name 'Week' => 'Sunday'


A formatted string which represents the specified date.

Type: string


Node.js (4〜)

Platform 4 5 6 7 8 9 10

io.js (1〜3)

Platform 1 2 3

Node.js (〜0.12)

Platform 0.8 0.9 0.10 0.11 0.12

Web browsers

Platform Chrome Firefox Vivaldi Safari Edge IE11
macOS -- --
Windows10 --
Linux -- -- --


Copyright (C) 2017-2018 Takayuki Sato

This program is free software under MIT License. See the file LICENSE in this distribution for more details.