Struct icu_calendar::chinese::Chinese

#[non_exhaustive]
pub struct Chinese;

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 fn new_always_calculating() -> Self

Construct a new Chinese without any precomputed calendrical calculations.

This is the only mode currently possible, but once precomputing is available (#3933) there will be additional constructors that load from data providers.

Trait Implementations

impl Calendar for Chinese

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

Obtain a name for the calendar for debug printing

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

The calendar-specific year represented by date

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

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

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

The AnyCalendarKind corresponding to this calendar

type DateInner = ChineseDateInner

The internal type used to represent dates

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

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

Calculate if a date is in a leap year

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 Hash for Chinese

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl IntoAnyCalendar for Chinese

fn to_any(self) -> AnyCalendar

Convert this calendar into an AnyCalendar, moving it

fn to_any_cloned(&self) -> AnyCalendar

Convert this calendar into an AnyCalendar, cloning it

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, other: &Chinese) -> Ordering

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for Chinese

fn eq(&self, other: &Chinese) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method 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, other: &Chinese) -> Option<Ordering>

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

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

This method tests less than (for self and other) and is used by the < operator.

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

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

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

This method tests greater than (for self and other) and is used by the > operator.

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

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

impl Eq for Chinese

impl StructuralEq for Chinese

impl StructuralPartialEq for Chinese