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Calendar

astrotime

Trait Calendar 

Source 
pub trait Calendar {
    // Required method
    fn is_gregorian() -> bool;

    // Provided methods
    fn name() -> &'static str { ... }
    fn epoch() -> Instant { ... }
    fn is_year_leap(year: i32) -> bool { ... }
    fn day_number(year: i32, month: u8, day: i64) -> Result<i64, Error> { ... }
    fn from_day_number(day_number: i64) -> Result<(i32, u8, u8), Error> { ... }
    fn month_days(month: u8, year: i32) -> u8 { ... }
}
Expand description

This specifies traditional Calendar settings that use the traditional 12 months and have leap years. This is implemented for Gregorian and Julian. It does not handle more esoteric calendars.

Zero and Negative years are handled in accordance with ISO 8601, such that year 0 is 1 B.C., and year -1 is 2 B.C., etc. In general:

  • n B.C. is represented by year 1-n
  • Year -y represents year y+1 B.C. (for positive y).

Required Methods§

Source

fn is_gregorian() -> bool

If the calendar is Gregorian (since we only handle Julian and Gregorian, this is all that needs to be defined to differentiate them)

Provided Methods§

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fn name() -> &'static str

The name of the calendar

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fn epoch() -> Instant

Epoch this calendar starts from

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fn is_year_leap(year: i32) -> bool

Answers the question: is this year a leap year?

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fn day_number(year: i32, month: u8, day: i64) -> Result<i64, Error>

Converts a year, month and (month)day into a day number which counts the number of days from the start of the calendar epoch

year may range from -2147483648 .. 2147483647 covering every possible i32.

month must be in the range 1 .. 12

day may be out of the normal bounds. It will be adjusted.

§Errors

Will return a Error::RangeError if month or day are out of range.

Source

fn from_day_number(day_number: i64) -> Result<(i32, u8, u8), Error>

Converts a day number which counts the number of days from the start of the calendar epoch into a year, month and day

For the Gregorian calendar, day_number must fall in the range -784_352_296_671 .. 784_352_295_938 which represent calendar dates -2147483648-01-01 .. 2147483647-12-31 respectively.

For the Julian calendar, day_number must fall in the range -784_368_402_798 .. 784_368_402_065 which represent calendar dates -2147483648-01-01 .. 2147483647-12-31 respectively.

Returns a (year, month, day)

§Errors

Will return a Error::RangeError if day_number is out of range.

§Panics

Panics on assertions that should only fail if there is a bug.

Source

fn month_days(month: u8, year: i32) -> u8

Returns the number of days in a given month (year is required for leap year calculations)

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§