calendar::jieqi Namespace Reference

Namespaces
namespace	detail

Classes
struct	JieqiGenerator
	A generator that generates consecutive Jieqis and their moments (in JDE), starting from a given JDE (exclusive). More...

Enumerations
enum class	Jieqi : uint8_t {   立春 , 雨水 , 惊蛰 , 春分 ,   清明 , 谷雨 , 立夏 , 小满 ,   芒种 , 夏至 , 小暑 , 大暑 ,   立秋 , 处暑 , 白露 , 秋分 ,   寒露 , 霜降 , 立冬 , 小雪 ,   大雪 , 冬至 , 小寒 , 大寒 ,   COUNT , LICHUN , YUSHUI , JINGZHE ,   CHUNFEN , QINGMING , GUYU , LIXIA ,   XIAOMAN , MANGZHONG , XIAZHI , XIAOSHU ,   DASHU , LIQIU , CHUSHU , BAILU ,   QIUFEN , HANLU , SHUANGJIANG , LIDONG ,   XIAOXUE , DAXUE , DONGZHI , XIAOHAN ,   DAHAN }
	The Chinese Jieqi (节气). More...

Functions
constexpr auto	is_jie (const Jieqi jq) -> bool
	Check if the given jq is a Jie (节).
constexpr auto	is_qi (const Jieqi jq) -> bool
	Check if the given jq is a Qi (气).
constexpr auto	to_index (const Jieqi jq) -> uint8_t
	Get the index of the given jq.
constexpr auto	from_index (const uint8_t index) -> Jieqi
	Get the Jieqi at a 0-based index counted from 立春.
constexpr auto	name_of (const Jieqi jq) -> std::string_view
	Get the name of the given jq.
constexpr auto	longitude_of (const Jieqi jq) -> double
	Get the solar longitude (in degrees) at which the given jq begins.
auto	calc_jieqi_jde (const int32_t year, const Jieqi jq) -> double
	Get the JDE for the given year and jieqi.
auto	jieqi_jde (const int32_t year, const Jieqi jq) -> double
	Get the JDE for the given year and jieqi, using cache.
auto	jieqi_ut1_moment (const int32_t year, const Jieqi jq) -> calendar::Datetime
	Get the UT1 moment of the given year and jieqi.

Variables
constexpr uint8_t	JIEQI_COUNT
constexpr auto	JIEQI_LIST
	A view of all enum values of Jieqi.
constexpr auto	GREGORIAN_YEAR_JIEQI_LIST
	Jieqi in Gregorian calendar order, beginning with 小寒.
constexpr std::array< std::string_view, JIEQI_COUNT >	JIEQI_NAME
	Name of each Jieqi, positioned by to_index.
constexpr std::array< double, JIEQI_COUNT >	JIEQI_SOLAR_LONGITUDE
	Solar longitude (in degrees) at which each Jieqi begins, positioned by to_index.

Enumeration Type Documentation

Jieqi

enum class calendar::jieqi::Jieqi : uint8_t

strong

The Chinese Jieqi (节气).

Enumerator
立春
雨水
惊蛰
春分
清明
谷雨
立夏
小满
芒种
夏至
小暑
大暑
立秋
处暑
白露
秋分
寒露
霜降
立冬
小雪
大雪
冬至
小寒
大寒
COUNT
LICHUN
YUSHUI
JINGZHE
CHUNFEN
QINGMING
GUYU
LIXIA
XIAOMAN
MANGZHONG
XIAZHI
XIAOSHU
DASHU
LIQIU
CHUSHU
BAILU
QIUFEN
HANLU
SHUANGJIANG
LIDONG
XIAOXUE
DAXUE
DONGZHI
XIAOHAN
DAHAN

Function Documentation

calc_jieqi_jde()

auto calendar::jieqi::calc_jieqi_jde ( const int32_t year, const Jieqi jq )->double

inlinenodiscard

Get the JDE for the given year and jieqi.

Parameters

year	The gregorian year, in [1, 32766].
jq	The jieqi.

Returns

The JDE (Julian Ephemeris Day).

Exceptions

std::invalid_argument	if year is outside [1, 32766], or jq is not a valid Jieqi.
std::runtime_error	if the root search does not yield exactly one root.

from_index()

auto calendar::jieqi::from_index ( const uint8_t index ) ->Jieqi

nodiscardconstexpr

Get the Jieqi at a 0-based index counted from 立春.

Parameters

index

The index, in [0, JIEQI_COUNT).

Returns

The jieqi.

Exceptions

std::invalid_argument

if index is not a valid index.

is_jie()

auto calendar::jieqi::is_jie ( const Jieqi jq ) ->bool

nodiscardconstexpr

Check if the given jq is a Jie (节).

Parameters

jq	The jieqi.

Returns

true if the given jq is a Jie (节), false otherwise.

is_qi()

auto calendar::jieqi::is_qi ( const Jieqi jq ) ->bool

nodiscardconstexpr

Check if the given jq is a Qi (气).

Parameters

jq	The jieqi.

Returns

true if the given jq is a Qi (气), false otherwise.

jieqi_jde()

auto calendar::jieqi::jieqi_jde ( const int32_t year, const Jieqi jq )->double

inlinenodiscard

Get the JDE for the given year and jieqi, using cache.

Parameters

year	The gregorian year, in [1, 32766].
jq	The jieqi.

Returns

The JDE (Julian Ephemeris Day).

Exceptions

std::invalid_argument	if year is outside [1, 32766], or jq is not a valid Jieqi.
std::runtime_error	if the root search does not yield exactly one root.

jieqi_ut1_moment()

auto calendar::jieqi::jieqi_ut1_moment ( const int32_t year, const Jieqi jq )->calendar::Datetime

inlinenodiscard

Get the UT1 moment of the given year and jieqi.

Parameters

year	The gregorian year, in [401, 32766].
jq	The jieqi.

Returns

The UT1 (Universal Time 1).

Exceptions

std::invalid_argument	if year is outside [401, 32766], or jq is not a valid Jieqi.
std::runtime_error	if the root search does not yield exactly one root.

Note

UT1, not UTC — the lunar-calendar rules render civil moments through the leap-second-aware path instead (#84). Remaining consumers: the C-ABI query_jieqi_moment (contract: celestial.h) and the HKO golden axis; UT1 stays for contract stability. While leap seconds are applied, |UT1 − UTC| < 0.9 s; past the last ΔAT table step the modelled UT1 − UTC is (ΔAT + 32.184 s) − ΔT, no longer bounded by 0.9 s (#115). The gap by era: docs/DESIGN.md#time-scales.

The returned date is not an east-eight wall date; rendering the same instant at a fixed UTC+8 offset can change its calendar date.

longitude_of()

auto calendar::jieqi::longitude_of ( const Jieqi jq ) ->double

nodiscardconstexpr

Get the solar longitude (in degrees) at which the given jq begins.

Parameters

jq	The jieqi.

Returns

The solar longitude.

Exceptions

std::invalid_argument

if jq is not a valid Jieqi.

name_of()

auto calendar::jieqi::name_of ( const Jieqi jq ) ->std::string_view

nodiscardconstexpr

Get the name of the given jq.

Parameters

jq	The jieqi.

Returns

The name.

Exceptions

std::invalid_argument

if jq is not a valid Jieqi.

to_index()

auto calendar::jieqi::to_index ( const Jieqi jq ) ->uint8_t

nodiscardconstexpr

Get the index of the given jq.

Parameters

jq	The jieqi.

Returns

The index of the given jq.

Variable Documentation

GREGORIAN_YEAR_JIEQI_LIST

auto calendar::jieqi::GREGORIAN_YEAR_JIEQI_LIST

inlineconstexpr

Jieqi in Gregorian calendar order, beginning with 小寒.

Note

This is calendar order; computed roots are not assumed to be chronological.

JIEQI_COUNT

uint8_t calendar::jieqi::JIEQI_COUNT

inlineconstexpr

JIEQI_LIST

auto calendar::jieqi::JIEQI_LIST

inlineconstexpr

A view of all enum values of Jieqi.

JIEQI_NAME

std::array<std::string_view, JIEQI_COUNT> calendar::jieqi::JIEQI_NAME

inlineconstexpr

Name of each Jieqi, positioned by to_index.

Note

Read it through name_of – a bare index cannot say which space it came from. See name_of.

JIEQI_SOLAR_LONGITUDE

std::array<double, JIEQI_COUNT> calendar::jieqi::JIEQI_SOLAR_LONGITUDE

inlineconstexpr

Solar longitude (in degrees) at which each Jieqi begins, positioned by to_index.

Note

Read it through longitude_of – see name_of.