# lunar-date-calculator

> converts between lunar and solar dates

Latest version **1.1.2** (published 2022-04-19) · ISC license · 0 weekly downloads

## Install

```sh
npm install lunar-date-calculator
pnpm add lunar-date-calculator
yarn add lunar-date-calculator
bun add lunar-date-calculator
```

## Health

**Score 20/100 (F)** — status: abandoned.

Positive: esm support; no vulnerabilities.

Warnings: low downloads; no types.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.1.2 |
| Published | 2022-04-19 |
| First published | 2022-04-12 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | none |
| Module format | ESM + CommonJS |
| Dependencies | 1 |
| Unpacked size | 4.5 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 2 |
| Author | Yujin Won |
| Maintainers | yujinwon |
| Keywords | lunar, date, lunisolar |

## Links

- npm: https://www.npmjs.com/package/lunar-date-calculator
- Repository: https://github.com/iamyujinwon/lunar-date-calculator
- Homepage: https://github.com/iamyujinwon/lunar-date-calculator#readme
- Issues: https://github.com/iamyujinwon/lunar-date-calculator/issues
- npm.io page: https://npm.io/package/lunar-date-calculator

## Dependencies (1)

- [solarlunar](https://npm.io/package/solarlunar.md) ^2.0.7

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## Recent versions

- 1.1.2 (latest) — 2022-04-19
- 1.1.1 — 2022-04-19
- 1.1.0 — 2022-04-19
- 1.0.5 — 2022-04-18
- 1.0.4 — 2022-04-18
- 1.0.3 — 2022-04-18
- 1.0.2 — 2022-04-12
- 1.0.1 — 2022-04-12

## README

# lunar-date-calculator

lunar-date-calculator is a Javascript library for converting the date to the solar date in the current or any target year.

## Installation

Use 'npm' to install the package.

```bash
npm i lunar-date-calculator
```

## Definition

### Lunar Calendar

> A lunar calendar is a calendar based on the monthly cycles of the Moon's phases (synodic months, lunations), in contrast to solar calendars, whose annual cycles are based only directly on the solar year. 


From [wikipedia](https://en.wikipedia.org/wiki/Lunar_calendar)

### Solar Calendar

> A solar calendar is a calendar whose dates indicate the season or almost equivalently the apparent position of the Sun relative to the stars. The Gregorian calendar, widely accepted as a standard in the world, is an example of a solar calendar. 


From [wikipedia](https://en.wikipedia.org/wiki/Solar_calendar)


## Usage

### fromSolarDate(solarYear, solarMonth, solarDay, targetYear = currentYear)

This function converts dates two times to get the solar date in the `currentYear` or any `targetYear`.

A `targetYear` is an optional parameter so that if `targetYear` is undefined, the default value is `currentYear`.

First, it converts the solar date to the lunar date in `solarYear`. 

If `targetYear` is defined, it converts the caculated lunar date to the solar date in the `targetYear`.

Otherwise, it converts the lunar date to the solar date in `currentYear`.

```javascript
import lunaDateCalculator from 'lunar-date-calculator';

// convert solar to lunar date in the current year (default value)
const solar2CurrentLunar = lunaDateCalculator.fromSolarDate(2007, 4, 18);
// output: { year: 2022, month: 4, day: 2 }

// convert solar in the future to lunar date in the target year
const solarInFuture2TargetLunar = lunaDateCalculator.fromSolarDate(2007, 4, 18, 1999);
// output: { year: 1999, month: 4, day: 17 }

// convert solar in the past to lunar date in the target year
const solarInPast2TargetLunar = lunaDateCalculator.fromSolarDate(2019, 4, 18, 2021);
// output: { year: 2021, month: 4, day: 13 }

```

### fromLunarDate(lunarYear, lunarMonth, lunarDay, targetYear = currentYear)

This function converts the lunar date to the solar date in the `currentYear` or any `targetYear`.

A `targetYear` is an optional parameter so that if `targetYear` is undefined, the default value is `currentYear`.

```javascript
import lunaDateCalculator from 'lunar-date-calculator';

// convert lunar to lunar date in the current year (default value)
const lunar2CurrentLunar = lunaDateCalculator.fromLunarDate(2007, 5, 15);
// output: { year: 2022, month: 6, day: 13 }

// convert lunar in the future to lunar date in the target year
const lunarInFuture2TargetLunar = lunaDateCalculator.fromLunarDate(2007, 5, 15, 1999);
// output: { year: 1999, month: 6, day: 28 }

// convert lunar in the past to lunar date in the target year
const lunarInPast2TargetLunar = lunaDateCalculator.fromLunarDate(2007, 5, 15, 2019);
// output: { year: 2019, month: 6, day: 17 }

```

---
_Source: https://npm.io/package/lunar-date-calculator · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._