Struct Gregorian 

pub struct Gregorian;

The Gregorian Calendar

The Gregorian calendar is an improvement over the Julian calendar. It was adopted under Pope Gregory XIII in 1582 CE by much of Roman Catholic Europe, and over the following centuries by all other countries that had been using the Julian calendar. Eventually even countries that had been using other calendars adopted this calendar, and today it is used as the international civil calendar.

This implementation extends proleptically for dates before the calendar’s creation.

This corresponds to the "gregory" CLDR calendar.

Era codes

This calendar uses two era codes: bce (alias bc), and ce (alias ad), corresponding to the BCE and CE eras.

Months and days

The 12 months are called January (M01, 31 days), February (M02, 28 days), March (M03, 31 days), April (M04, 30 days), May (M05, 31 days), June (M06, 30 days), July (M07, 31 days), August (M08, 31 days), September (M09, 30 days), October (M10, 31 days), November (M11, 30 days), December (M12, 31 days).

In leap years (years divisible by 4 but not 100 except when divisble by 400), February gains a 29th day.

Standard years thus have 365 days, and leap years 366.

Calendar drift

The Gregorian calendar has an average year length of 365.2425, slightly longer than the mean solar year, so this calendar drifts 1 day in ~7700 years with respect to the seasons.

Historical accuracy

This type implements the proleptic Gregorian calendar, with dates before 1582 CE using the rules projected backwards. Care needs to be taken when intepreting historical dates before or during the transition from the Julian to the Gregorian calendar. Some regions continued using the Julian calendar as late as the 20th century. Sources often mark dates as “New Style” (Gregorian) or “Old Style” (Julian) if there is ambiguity.

Historically, the Julian/Gregorian calendars were used with a variety of year reckoning schemes (see Julian for more detail). The Gregorian calendar has generally been used with the Anno Domini/Common era since its inception. However, some countries that have adopted the Gregorian calendar more recently are still using their traditional year-reckoning schemes. This crate implements some of these as different types, i.e the Thai Buddhist calendar, the Japanese calendar, and the Chinese Republican Calendar (Roc).

Implementations

impl Gregorian

pub fn easter(year: i32) -> Date<Gregorian>

Returns the date of Easter in the given year.

Trait Implementations

impl Calendar for Gregorian

type DateInner = GregorianDateInner

The internal type used to represent dates

type Year = EraYear

The type of YearInfo returned by the date

type DifferenceError = Infallible

The type of error returned by until

fn from_codes( &self, era: Option<&str>, year: i32, month_code: MonthCode, day: u8, ) -> Result<<Gregorian as Calendar>::DateInner, DateError>

Construct a date from era/month codes and fields

fn from_rata_die(&self, rd: RataDie) -> <Gregorian as Calendar>::DateInner

Construct the date from a RataDie

fn to_rata_die(&self, date: &<Gregorian as Calendar>::DateInner) -> RataDie

Obtain a RataDie from this date

fn has_cheap_iso_conversion(&self) -> bool

Whether from_iso/to_iso is more efficient than from_rata_die/to_rata_die.

fn from_iso(&self, iso: IsoDateInner) -> <Gregorian as Calendar>::DateInner

Construct the date from an ISO date.

fn to_iso(&self, date: &<Gregorian as Calendar>::DateInner) -> IsoDateInner

Obtain an ISO date from this date.

fn months_in_year(&self, date: &<Gregorian as Calendar>::DateInner) -> u8

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

fn days_in_year(&self, date: &<Gregorian as Calendar>::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: &<Gregorian as Calendar>::DateInner) -> u8

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

fn year_info( &self, date: &<Gregorian as Calendar>::DateInner, ) -> <Gregorian as Calendar>::Year

Information about the year

fn is_in_leap_year(&self, date: &<Gregorian as Calendar>::DateInner) -> bool

Calculate if a date is in a leap year

fn month(&self, date: &<Gregorian as Calendar>::DateInner) -> MonthInfo

The calendar-specific month represented by date

fn day_of_month(&self, date: &<Gregorian as Calendar>::DateInner) -> DayOfMonth

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

fn day_of_year(&self, date: &<Gregorian as Calendar>::DateInner) -> DayOfYear

Information of the day of the year

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

Obtain a name for the calendar for debug printing

fn calendar_algorithm(&self) -> Option<CalendarAlgorithm>

Returns the CalendarAlgorithm that is required to match when parsing into this calendar.

fn extended_year(&self, date: &Self::DateInner) -> i32

The extended year.

impl CldrCalendar for Gregorian

type YearNamesV1 = DatetimeNamesYearGregorianV1

The data marker for loading year symbols for this calendar.

type MonthNamesV1 = DatetimeNamesMonthGregorianV1

The data marker for loading month symbols for this calendar.

type SkeletaV1 = DatetimePatternsDateGregorianV1

The data marker for loading skeleton patterns for this calendar.

impl Clone for Gregorian

fn clone(&self) -> Gregorian

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Gregorian

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

Formats the value using the given formatter.

impl Default for Gregorian

fn default() -> Gregorian

Returns the “default value” for a type.

impl From<Gregorian> for AnyCalendar

fn from(value: Gregorian) -> AnyCalendar

Converts to this type from the input type.

impl IntoAnyCalendar for Gregorian

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 from_any(any: AnyCalendar) -> Result<Gregorian, 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<&Gregorian>

Convert an AnyCalendar reference into a Self reference.

fn date_to_any(&self, d: &<Gregorian as Calendar>::DateInner) -> AnyDateInner

Convert a date for this calendar into an AnyDateInner

impl Copy for Gregorian

impl IntoFormattableAnyCalendar for Gregorian

impl UnstableSealed for Gregorian