warera

A lightweight Javascript/Typescript library for mutual conversion Japanese Calendar Date and Gregorian Calendar Date

Documentation

npm i warera

Gregorian Calendar to Japanese Calendar

date.getJapaneseCalendarDate()

Example

const date = warera(new Date(2019, 4, 1)); // 2019-05-01

console.log(date.getJapaneseCalendarDate());
//  is return value as...
//
//  {
//      era: {
//          long: '令和',
//          short: 'R
//      },
//      year: 1,
//      month: 5,
//      day: 1
//  }

Japanese Calendar to Gregorian Calendar

getDate()

Example

const date = warera({era: 'R', year: 1, month: 5, day: 1});
// or
const date = warera({era: '令和', year: 1, month: 5, day: 1});

console.log(date.getDate())
// is return value as Date class (Wed May 01 2019 00:00:00 GMT+0900)

Formatter

date.format(pattern: string, replaceToGanForFirstYear: boolean);

Example

const date = warera({era: 'R', year: 1, month: 5, day: 1});
date.format('WWWkky年kkM月kkD日') // '令和元年五月一日'

Arguments

'pattern'

| Input | Example | Description | | :---- | :------ | :------------------------------------------------------- | | YYYY | 2019 | Gregorian calendar 4 digit year | | WWW | 令和 | Japanese calendar era (Full name of kanji) | | W | R | Japanese calendar era (Alphabet) | | kky | 二十一 | Japanese calendar year (Japanese numeral long) | | ky | 二一 | Japanese calendar year (Japanese numeral short) | | ddy | 弐拾壱 | Japanese calendar year (Japanese numeral long old char) | | dy | 弐壱 | Japanese calendar year (Japanese numeral short old char) | | yy | 01 | Japanese calendar year (Arabic numeral padded by 0) | | y | 1 | Japanese calendar year (Arabic numeral) | | kkM | 二十一 | Month (Japanese numeral long) | | kM | 二一 | Month (Japanese numeral short) | | ddM | 弐拾壱 | Month (Japanese numeral long old char) | | dM | 弐壱 | Month (Japanese numeral short old char) | | MM | 01 | Month (Arabic numeral padded by 0) | | M | 1 | Month (Arabic numeral) | | kkD | 二十一 | Day (Japanese numeral long) | | kD | 二一 | Day (Japanese numeral short) | | ddD | 弐拾壱 | Day (Japanese numeral long old char) | | dD | 弐壱 | Day (Japanese numeral short old char) | | DD | 01 | Day (Arabic numeral padded by 0) | | D | 1 | Day (Arabic numeral) |

'replaceToGanForFirstYear'

In Japan, the first year when the era begins is sometimes called the "元年".
"元年" meaning "first year".

When 'replaceToGanForFirstYear' true,

const date = warera({era: 'R', year: 1, month: 5, day: 1}, true);
date.format('WWWkky年kkM月kkD日') // '令和元年五月一日'

When false,

const date = warera({era: 'R', year: 1, month: 5, day: 1});
date.format('WWWkky年kkM月kkD日') // '令和一年五月一日'

What's 'warera' ?

'warera' is coined word by 'wareki' (meaning Japanese Calendar) and 'era'!