Struct Time

Source

pub struct Time<S: TimeScale> { /* private fields */ }

Expand description

A point on time scale S.

Internally stores a single Days quantity whose interpretation depends on S: TimeScale. The struct is Copy and zero-cost: PhantomData is zero-sized, so Time<S> is layout-identical to Days (a single f64).

Implementations§

Source §

impl Time<UT>

Source

pub fn delta_t(&self) -> Seconds

Returns ΔT = TT − UT in seconds for this UT epoch.

This is a convenience accessor; the same correction is applied automatically when converting to any TT-based scale (.to::<JD>()).

Source §

impl<S: TimeScale> Time<S>

Source

pub const fn new(value: f64) -> Self

Create from a raw scalar (days since the scale’s epoch).

Note: this constructor accepts any f64, including NaN and ±∞. Prefer try_new when the value comes from untrusted or computed input.

Source

pub fn try_new(value: f64) -> Result<Self, NonFiniteTimeError>

Create from a raw scalar, rejecting non-finite values.

Returns NonFiniteTimeError if value is NaN, +∞, or −∞.

§Examples

use tempoch::{Time, JD};

assert!(Time::<JD>::try_new(2451545.0).is_ok());
assert!(Time::<JD>::try_new(f64::NAN).is_err());
assert!(Time::<JD>::try_new(f64::INFINITY).is_err());

Source

pub const fn from_days(days: Days) -> Self

Create from a Days quantity.

Note: this constructor accepts any f64, including NaN and ±∞. Prefer try_from_days when the value comes from untrusted or computed input.

Source

pub fn try_from_days(days: Days) -> Result<Self, NonFiniteTimeError>

Create from a Days quantity, rejecting non-finite values.

Returns NonFiniteTimeError if the underlying value is NaN, +∞, or −∞.

Source

pub const fn quantity(&self) -> Days

The underlying quantity in days.

Source

pub const fn value(&self) -> f64

The underlying scalar value in days.

Source

pub fn julian_day(&self) -> Days

Absolute Julian Day (TT) corresponding to this instant.

Source

pub fn julian_day_value(&self) -> f64

Absolute Julian Day (TT) as scalar.

Source

pub fn from_julian_day(jd: Days) -> Self

Build an instant from an absolute Julian Day (TT).

Source

pub fn to<T: TimeScale>(&self) -> Time<T>

Convert this instant to another time scale.

The conversion routes through the canonical JD(TT) intermediate:

self → JD(TT) → target

For pure epoch-offset scales this compiles down to a single addition/subtraction.

Source

pub fn to_utc(&self) -> Option<DateTime<Utc>>

Convert to a chrono::DateTime<Utc>.

Inverts the ΔT correction to recover the UTC / UT timestamp. Returns None if the value falls outside chrono’s representable range.

Source

pub fn from_utc(datetime: DateTime<Utc>) -> Self

Build an instant from a chrono::DateTime<Utc>.

The UTC timestamp is interpreted as Universal Time (≈ UT1) and the epoch-dependent ΔT correction is applied automatically, so the resulting Time<S> is on the target scale’s axis.

Source

pub const fn min(self, other: Self) -> Self

Element-wise minimum.

Source

pub const fn max(self, other: Self) -> Self

Element-wise maximum.

Source

pub const fn mean(self, other: Self) -> Self

Mean (midpoint) between two instants on the same time scale.

Source §

impl Time<JD>

Source

pub const J2000: Self

J2000.0 epoch: 2000-01-01T12:00:00 TT (JD 2 451 545.0).

Source

pub const JULIAN_YEAR: Days

One Julian year expressed in days.

Source

pub const JULIAN_CENTURY: Days

One Julian century expressed in days.

Source

pub const JULIAN_MILLENNIUM: Days

One Julian millennium expressed in days.

Source

pub fn julian_millennias(&self) -> Millennia

Julian millennia since J2000.0 (used by VSOP87).

Source

pub fn julian_centuries(&self) -> Centuries

Julian centuries since J2000.0 (used by nutation, precession, sidereal time).

Source

pub fn julian_years(&self) -> JulianYears

Julian years since J2000.0.

Source

pub fn tt_to_tdb(jd_tt: Self) -> Self

Converts JD(TT) → JD(TDB) using the Fairhead & Bretagnon (1990) expression for TDB − TT.

The dominant term has an amplitude of ≈1.658 ms. This implementation includes the four largest periodic terms plus a secular component, matching the formula recommended by USNO Circular 179 (Kaplan 2005) and consistent with IAU 2006 Resolution B3.

Accuracy: better than 30 μs for dates within ±10 000 years of J2000.

§References

Fairhead & Bretagnon (1990), A&A 229, 240
USNO Circular 179, eq. 2.6
SOFA iauDtdb (full implementation has hundreds of terms)

Source

pub fn to_mjd(&self) -> Time<MJD>

Convenience: MJD value corresponding to this JD.

Kept as a convenience wrapper for self.to::<MJD>().

Trait Implementations§

Source §

impl<S: TimeScale> Add<Quantity<Day>> for Time<S>

Source §

type Output = Time<S>

The resulting type after applying the + operator.

Source §

fn add(self, rhs: Days) -> Self::Output

Performs the + operation. Read more

Source §

impl Add<Quantity<Year>> for Time<JD>

Source §

type Output = Time<JD>

The resulting type after applying the + operator.

Source §

fn add(self, years: Years) -> Self

Performs the + operation. Read more

Source §

impl<S: TimeScale> AddAssign<Quantity<Day>> for Time<S>

Source §

fn add_assign(&mut self, rhs: Days)

Performs the += operation. Read more

Source §

impl<S: Clone + TimeScale> Clone for Time<S>

Source §

fn clone(&self) -> Time<S>

Returns a duplicate of the value. Read more

1.0.0 · Source§

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

Performs copy-assignment from source. Read more

Source §

impl<S: Debug + TimeScale> Debug for Time<S>

Source §

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

Formats the value using the given formatter. Read more

Source §

impl<S: TimeScale> Display for Time<S>

Source §

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

Formats the value using the given formatter. Read more

Source §

impl<S: TimeScale> Div<Quantity<Day>> for Time<S>

Source §

type Output = f64

The resulting type after applying the / operator.

Source §

fn div(self, rhs: Days) -> Self::Output

Performs the / operation. Read more

Source §

impl<S: TimeScale> Div<f64> for Time<S>

Source §

type Output = f64

The resulting type after applying the / operator.

Source §

fn div(self, rhs: f64) -> Self::Output

Performs the / operation. Read more

Source §