Crate lunar_lite 

lunar-lite is a small library for Chinese lunisolar date conversion.

It converts between the Gregorian (solar) calendar and the Chinese lunar calendar, and exposes the sexagenary cycle (六十甲子) of Heavenly Stems and Earthly Branches.

Examples

use lunar_lite::{solar_to_lunar, lunar_to_solar, SolarDate, LunarDate};

let solar = SolarDate { year: 2024, month: 2, day: 10 };
let lunar = solar_to_lunar(solar).unwrap();
assert_eq!(lunar, LunarDate { year: 2024, month: 1, day: 1, is_leap_month: false });

// Round-trips back to the original solar date.
assert_eq!(lunar_to_solar(lunar).unwrap(), solar);

Supported range

Conversions are backed by a generated table of per-year data; years outside the supported range return LunarError::YearOutOfRange.

Features

• serde: derive Serialize/Deserialize for the public date and stem-branch types.

Structs

FourPillars

The four pillars (年柱, 月柱, 日柱, 时柱) of a date and time.

LunarDate

A date in the Chinese lunar calendar.

SolarDate

A date in the Gregorian (solar) calendar.

StemBranch

A valid Heavenly Stem / Earthly Branch pair in the sexagenary cycle.

StemBranchOptions

Options controlling the year and month pillar boundaries.

Enums

EarthlyBranch

One of the twelve Earthly Branches.

HeavenlyStem

One of the ten Heavenly Stems.

LunarError

Errors from date conversion and validation.

MonthDivide

How to resolve the month pillar across the month boundary.

StemBranchError

Errors from constructing a StemBranch.

YearDivide

How to resolve the year pillar across the year boundary.

Constants

EARTHLY_BRANCHES

Canonical cyclic ordering of the twelve Earthly Branches.

HEAVENLY_STEMS

Canonical cyclic ordering of the ten Heavenly Stems.

Functions

four_pillars_from_solar_date

Rust-native alias for get_heavenly_stem_and_earthly_branch_by_solar_date (default Exact/Exact options).

four_pillars_from_solar_date_with_options

Rust-native alias for get_heavenly_stem_and_earthly_branch_by_solar_date_with_options.

get_heavenly_stem_and_earthly_branch_by_solar_date

Computes the four pillars for a Gregorian solar date and 时辰 index, using the default (StemBranchOptions::default, i.e. Exact/Exact, matching lunar-lite@0.2.8).

get_heavenly_stem_and_earthly_branch_by_solar_date_with_options

Computes the four pillars for a Gregorian solar date and 时辰 index with explicit StemBranchOptions.

is_early_zi

Returns true if time_index is the early 子时 (0, 00:00–00:59).

is_late_zi

Returns true if time_index is the late 子时 (12, 23:00–23:59).

lunar_to_solar

Converts a Chinese lunar date to its Gregorian (solar) date.

lunar_year_branch

Returns the Earthly Branch of a Chinese lunar year (生年支).

lunar_year_stem

Returns the Heavenly Stem of a Chinese lunar year (生年干).

lunar_year_stem_branch

Returns the stem-branch of a Chinese lunar year.

normalize_lunar_date

Normalizes a lunar date and verifies that it actually exists.

solar_to_lunar

Converts a Gregorian (solar) date to its Chinese lunar date.

time_index

Returns the double-hour (時辰) index for a wall-clock time.

time_index_to_branch

Returns the Earthly Branch (时支) for a 时辰 index.

Type Aliases

HeavenlyStemAndEarthlyBranchDate

Compatibility alias mirroring the TypeScript lunar-lite result name.