Struct JulianDate 

pub struct JulianDate { /* private fields */ }

Julian date representation for astronomical calculations.

Follows the SPA algorithm described in Reda & Andreas (2003). Supports both Julian Date (JD) and Julian Ephemeris Date (JDE) calculations.

Implementations

impl JulianDate

pub fn from_datetime<Tz: TimeZone>( datetime: &DateTime<Tz>, delta_t: f64, ) -> Result<Self>

Creates a new Julian date from a timezone-aware chrono DateTime.

Converts datetime to UTC for proper Julian Date calculation.

Arguments

• datetime - Timezone-aware date and time
• delta_t - ΔT in seconds (difference between TT and UT1)

Returns

Returns Ok(JulianDate) on success.

Errors

Returns error if the date/time components are invalid (e.g., invalid month, day, hour).

pub fn from_utc( year: i32, month: u32, day: u32, hour: u32, minute: u32, second: f64, delta_t: f64, ) -> Result<Self>

Creates a new Julian date from year, month, day, hour, minute, and second in UTC.

Arguments

• year - Year (can be negative for BCE years)
• month - Month (1-12)
• day - Day of month (1-31)
• hour - Hour (0-23)
• minute - Minute (0-59)
• second - Second (0-59, can include fractional seconds)
• delta_t - ΔT in seconds (difference between TT and UT1)

Returns

Julian date or error if the date is invalid

Errors

Returns error if any date/time component is outside valid ranges (month 1-12, day 1-31, hour 0-23, minute 0-59, second 0-59.999).

Example

let jd = JulianDate::from_utc(2023, 6, 21, 12, 0, 0.0, 69.0).unwrap();
assert!(jd.julian_date() > 2_460_000.0);

pub fn from_utc_simple( year: i32, month: u32, day: u32, hour: u32, minute: u32, second: f64, ) -> Result<Self>

Creates a Julian date assuming ΔT = 0.

Arguments

• year - Year (can be negative for BCE years)
• month - Month (1-12)
• day - Day of month (1-31)
• hour - Hour (0-23)
• minute - Minute (0-59)
• second - Second (0-59, can include fractional seconds)

Returns

Returns Ok(JulianDate) with ΔT = 0 on success.

Errors

Returns error if the date/time components are outside valid ranges.

pub const fn julian_date(&self) -> f64

Gets the Julian Date (JD) value.

Returns

Julian Date referenced to UT1

pub const fn delta_t(&self) -> f64

Gets the ΔT value in seconds.

Returns

ΔT (Delta T) in seconds

pub fn julian_ephemeris_day(&self) -> f64

Calculates the Julian Ephemeris Day (JDE).

JDE = JD + ΔT/86400

Returns

Julian Ephemeris Day

pub fn julian_century(&self) -> f64

Calculates the Julian Century (JC) from J2000.0.

JC = (JD - 2451545.0) / 36525

Returns

Julian centuries since J2000.0 epoch

pub fn julian_ephemeris_century(&self) -> f64

Calculates the Julian Ephemeris Century (JCE) from J2000.0.

JCE = (JDE - 2451545.0) / 36525

Returns

Julian ephemeris centuries since J2000.0 epoch

pub fn julian_ephemeris_millennium(&self) -> f64

Calculates the Julian Ephemeris Millennium (JME) from J2000.0.

JME = JCE / 10

Returns

Julian ephemeris millennia since J2000.0 epoch

Trait Implementations

impl Clone for JulianDate

fn clone(&self) -> JulianDate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for JulianDate

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

Formats the value using the given formatter.

impl PartialEq for JulianDate

fn eq(&self, other: &JulianDate) -> 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 Copy for JulianDate

impl StructuralPartialEq for JulianDate