Struct Date

pub struct Date { /* private fields */ }

Implementation of a date in the historic calendar. After 15 October 1582, this coincides with the Gregorian calendar; until 4 October 1582, this is the Julian calendar. The days inbetween do not exist.

This is the calendar that is also used by IAU SOFA and NAIF SPICE, as well as Meeus in his Astronomical Algorithms book. Hence, most users probably expect it to be the calendar of choice.

Implementations

impl Date

pub const fn new( year: i32, month: Month, day: u8, ) -> Result<Self, InvalidHistoricDate>

Creates a new date, given its year, month, and day. If the date is not a valid date in the historic calendar, returns a DateDoesNotExist error to indicate that the requested date does not exist.

This function will never panic.

pub const fn from_year_day( year: i32, day_of_year: u16, ) -> Result<Self, InvalidDayOfYear>

Creates a new date given only the year and the day-of-year. Implementation is based on an algorithm found by A. Pouplier and reported by Jean Meeus in Astronomical Algorithms.

This function will never panic.

pub const fn to_local_days(self) -> LocalDays<i64>

Constructs a MJD from a given historic calendar date. Applies a slight variation on the approach described by Meeus in Astronomical Algorithms (Chapter 7, Julian Day). This variation adapts the algorithm to the Unix epoch and removes the dependency on floating point arithmetic.

pub const fn year(&self) -> i32

Returns the year stored inside this proleptic Gregorian date. Astronomical year numbering is used (as also done in NAIF SPICE): the year 1 BCE is represented as 0, 2 BCE as -1, etc. Hence, around the year 0, the numbering is …, -2 (3 BCE), -1 (2 BCE), 0 (1 BCE), 1 (1 CE), 2 (2 CE), et cetera. In this manner, the year numbering proceeds smoothly through 0.

pub const fn month(&self) -> Month

Returns the month stored inside this proleptic Gregorian date.

pub const fn day(&self) -> u8

Returns the day-of-month stored inside this proleptic Gregorian date.

pub const fn day_of_year(&self) -> u16

Returns the day-of-year of this specific date, within its calendar year. The day-of-year is an integer value ranging from 1 on January 1 to 365 (or 365, in leap years) on December 31. Uses the algorithm given by Meeus in Astronomical Algorithms.

pub const fn is_gregorian(&self) -> bool

Returns whether the current date falls within the Gregorian (true) or Julian (false) part of the historic calendar.

pub const fn days_in_month(year: i32, month: Month) -> u8

Returns the number of days in a given month of a year. Also considers whether the given year-month combination would fall in the Gregorian or Julian calendar.

Trait Implementations

impl Clone for Date

fn clone(&self) -> Date

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Date

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

Formats the value using the given formatter.

impl From<Date> for LocalDays<i64>

fn from(value: Date) -> Self

Converts to this type from the input type.

impl Ord for Date

fn cmp(&self, other: &Date) -> 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,

Restrict a value to a certain interval.

impl PartialEq for Date

fn eq(&self, other: &Date) -> 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 Date

fn partial_cmp(&self, other: &Date) -> 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 Sub for Date

fn sub(self, rhs: Self) -> Self::Output

The difference between two Gregorian dates can be computed exactly as a number of days, accounting for the variable number of days per leap year. Note that this is only possible up to an accuracy of days because leap seconds depend on the time scale.

type Output = Duration<i64, LiteralRatio<86400>>

The resulting type after applying the - operator.

impl Copy for Date

impl Eq for Date

impl StructuralPartialEq for Date