Struct icu_calendar::cal::Chinese

pub struct Chinese { /* private fields */ }

The Chinese Calendar

The [Chinese Calendar] is a lunisolar calendar used traditionally in China as well as in other countries particularly in, but not limited to, East Asia. It is often used today to track important cultural events and holidays like the Chinese Lunar New Year.

This type can be used with Date or DateTime to represent dates in the Chinese calendar.

Months

The Chinese calendar is an astronomical calendar which uses the phases of the moon to track months. Each month starts on the date of the new moon as observed from China, meaning that months last 29 or 30 days.

One year in the Chinese calendar is typically 12 lunar months; however, because 12 lunar months does not line up to one solar year, the Chinese calendar will add an intercalary leap month approximately every three years to keep Chinese calendar months in line with the solar year.

Leap months can happen after any month; the month in which a leap month occurs is based on the alignment of months with 24 solar terms into which the solar year is divided.

Year and Era codes

Unlike the Gregorian calendar, the Chinese calendar does not traditionally count years in an infinitely increasing sequence. Instead, 10 “celestial stems” and 12 “terrestrial branches” are combined to form a cycle of year names which repeats every 60 years. However, for the purposes of calendar calculations and conversions, this module counts Chinese years in an infinite system similar to ISO, with year 1 in the calendar corresponding to the inception of the calendar, marked as 2637 BCE (ISO: -2636), and negative years marking Chinese years before February 15, 2637 BCE.

Because the Chinese calendar does not traditionally count years, era codes are not used in this calendar; this crate supports a single era code “chinese”.

This Chinese calendar implementation also supports a related ISO year, which marks the ISO year in which a Chinese year begins, and a cyclic year corresponding to the year in the 60 year cycle as described above.

For more information, suggested reading materials include:

• Calendrical Calculations by Reingold & Dershowitz
• The Mathematics of the Chinese Calendar by Helmer Aslaksen https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.139.9311&rep=rep1&type=pdf
• Wikipedia: https://en.wikipedia.org/wiki/Chinese_calendar

Month codes

This calendar is a lunisolar calendar. It supports regular month codes "M01" - "M12" as well as leap month codes "M01L" - "M12L".

This calendar is currently in a preview state: formatting for this calendar is not going to be perfect.

Implementations

impl Chinese

pub const fn new() -> Self

Creates a new Chinese with some precomputed calendrical calculations.

✨ Enabled with the compiled_data Cargo feature.

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pub fn try_new_with_any_provider( provider: &(impl AnyProvider + ?Sized), ) -> Result<Self, DataError>

A version of [Self :: new] that uses custom data provided by an AnyProvider.

📚 Help choosing a constructor

pub fn try_new_with_buffer_provider( provider: &(impl BufferProvider + ?Sized), ) -> Result<Self, DataError>

A version of [Self :: new] that uses custom data provided by a BufferProvider.

✨ Enabled with the serde feature.

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pub fn try_new_unstable<D: DataProvider<ChineseCacheV1Marker> + ?Sized>( provider: &D, ) -> Result<Self, DataError>

A version of Self::new that uses custom data provided by a DataProvider.

📚 Help choosing a constructor

⚠️ The bounds on provider may change over time, including in SemVer minor releases.

pub fn new_always_calculating() -> Self

Construct a new Chinese without any precomputed calendrical calculations.

Trait Implementations

impl Calendar for Chinese

fn debug_name(&self) -> &'static str

Obtain a name for the calendar for debug printing

fn month(&self, date: &Self::DateInner) -> MonthInfo

The calendar-specific month code represented by date; since the Chinese calendar has leap months, an “L” is appended to the month code for leap months. For example, in a year where an intercalary month is added after the second month, the month codes for ordinal months 1, 2, 3, 4, 5 would be “M01”, “M02”, “M02L”, “M03”, “M04”.

fn day_of_month(&self, date: &Self::DateInner) -> DayOfMonth

The calendar-specific day-of-month represented by date

fn day_of_year_info(&self, date: &Self::DateInner) -> DayOfYearInfo

Information of the day of the year

type DateInner = ChineseDateInner

The internal type used to represent dates

fn date_from_codes( &self, era: Option<Era>, year: i32, month_code: MonthCode, day: u8, ) -> Result<Self::DateInner, DateError>

Construct a date from era/month codes and fields

fn date_from_iso(&self, iso: Date<Iso>) -> Self::DateInner

Construct the date from an ISO date

fn date_to_iso(&self, date: &Self::DateInner) -> Date<Iso>

Obtain an ISO date from this date

fn days_in_year(&self, date: &Self::DateInner) -> u16

Count the number of days in a given year, specified by providing a date from that year

fn days_in_month(&self, date: &Self::DateInner) -> u8

Count the number of days in a given month, specified by providing a date from that year/month

fn year(&self, date: &Self::DateInner) -> YearInfo

Information about the year

fn is_in_leap_year(&self, date: &Self::DateInner) -> bool

Calculate if a date is in a leap year

fn any_calendar_kind(&self) -> Option<AnyCalendarKind>

The AnyCalendarKind corresponding to this calendar, if one exists. Implementors outside of icu::calendar should return None

fn months_in_year(&self, date: &Self::DateInner) -> u8

Count the number of months in a given year, specified by providing a date from that year

fn day_of_week(&self, date: &Self::DateInner) -> IsoWeekday

Calculate the day of the week and return it

impl Clone for Chinese

fn clone(&self) -> Chinese

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Chinese

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Chinese

fn default() -> Chinese

Returns the “default value” for a type.

impl From<Chinese> for AnyCalendar

fn from(value: Chinese) -> AnyCalendar

Converts to this type from the input type.

impl IntoAnyCalendar for Chinese

fn to_any(self) -> AnyCalendar

Convert this calendar into an AnyCalendar, moving it

fn kind(&self) -> AnyCalendarKind

The AnyCalendarKind enum variant associated with this calendar

fn to_any_cloned(&self) -> AnyCalendar

Convert this calendar into an AnyCalendar, cloning it

fn from_any(any: AnyCalendar) -> Result<Self, AnyCalendar>

Move an AnyCalendar into a Self, or returning it as an error if the types do not match.

fn from_any_ref(any: &AnyCalendar) -> Option<&Self>

Convert an AnyCalendar reference into a Self reference.

fn date_to_any(&self, d: &Self::DateInner) -> AnyDateInner

Convert a date for this calendar into an AnyDateInner

impl Ord for Chinese

fn cmp(&self, _: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for Chinese

fn eq(&self, _: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Chinese

fn partial_cmp(&self, _: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for Chinese