Struct Time 

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

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

impl Time<UT>

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>()).

impl<S: TimeScale> Time<S>

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

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

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

Create from a Days quantity.

pub const fn quantity(&self) -> Days

The underlying quantity in days.

pub const fn value(&self) -> f64

The underlying scalar value in days.

pub fn julian_day(&self) -> Days

Absolute Julian Day (TT) corresponding to this instant.

pub fn julian_day_value(&self) -> f64

Absolute Julian Day (TT) as scalar.

pub fn from_julian_day(jd: Days) -> Self

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

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.

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.

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.

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

Element-wise minimum.

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

Element-wise maximum.

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

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

impl Time<JD>

pub const J2000: Self

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

pub const JULIAN_YEAR: Days

One Julian year expressed in days.

pub const JULIAN_CENTURY: Days

One Julian century expressed in days.

pub const JULIAN_MILLENNIUM: Days

One Julian millennium expressed in days.

pub fn julian_millennias(&self) -> Millennia

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

pub fn julian_centuries(&self) -> Centuries

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

pub fn julian_years(&self) -> JulianYears

Julian years since J2000.0.

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)

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

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

type Output = Time<S>

The resulting type after applying the + operator.

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

Performs the + operation.

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

type Output = Time<JD>

The resulting type after applying the + operator.

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

Performs the + operation.

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

fn add_assign(&mut self, rhs: Days)

Performs the += operation.

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

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

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

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

Formats the value using the given formatter.

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

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

Formats the value using the given formatter.

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

type Output = f64

The resulting type after applying the / operator.

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

Performs the / operation.

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

type Output = f64

The resulting type after applying the / operator.

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

Performs the / operation.

impl From<Quantity<Century>> for Time<JD>

fn from(centuries: Centuries) -> Self

Converts to this type from the input type.

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

fn from(days: Days) -> Self

Converts to this type from the input type.

impl From<Quantity<JulianYear>> for Time<JD>

fn from(years: JulianYears) -> Self

Converts to this type from the input type.

impl From<Quantity<Millennium>> for Time<JD>

fn from(millennia: Millennia) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<JD>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<JDE>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<MJD>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<TAI>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<TCB>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<TCG>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<TDB>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<TT>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<UT>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<GPS>> for Time<UnixTime>

fn from(t: Time<GPS>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Centuries

fn from(jd: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for JulianYears

fn from(jd: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Millennia

fn from(jd: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<GPS>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<JDE>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<MJD>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<TAI>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<TCB>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<TCG>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<TDB>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<TT>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<UT>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JD>> for Time<UnixTime>

fn from(t: Time<JD>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<GPS>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<JD>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<MJD>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<TAI>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<TCB>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<TCG>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<TDB>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<TT>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<UT>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<JDE>> for Time<UnixTime>

fn from(t: Time<JDE>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<GPS>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<JD>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<JDE>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<TAI>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<TCB>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<TCG>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<TDB>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<TT>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<UT>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl From<Time<MJD>> for Time<UnixTime>

fn from(t: Time<MJD>) -> Self

Converts to this type from the input type.

impl<S: TimeScale> From<Time<S>> for Days

fn from(time: Time<S>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<GPS>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<JD>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<JDE>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<MJD>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<TCB>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<TCG>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<TDB>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<TT>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<UT>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TAI>> for Time<UnixTime>

fn from(t: Time<TAI>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<GPS>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<JD>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<JDE>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<MJD>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<TAI>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<TCG>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<TDB>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<TT>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<UT>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCB>> for Time<UnixTime>

fn from(t: Time<TCB>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<GPS>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<JD>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<JDE>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<MJD>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<TAI>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<TCB>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<TDB>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<TT>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<UT>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TCG>> for Time<UnixTime>

fn from(t: Time<TCG>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<GPS>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<JD>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<JDE>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<MJD>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<TAI>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<TCB>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<TCG>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<TT>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<UT>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TDB>> for Time<UnixTime>

fn from(t: Time<TDB>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<GPS>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<JD>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<JDE>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<MJD>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<TAI>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<TCB>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<TCG>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<TDB>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<UT>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<TT>> for Time<UnixTime>

fn from(t: Time<TT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<GPS>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<JD>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<JDE>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<MJD>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<TAI>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<TCB>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<TCG>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<TDB>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<TT>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UT>> for Time<UnixTime>

fn from(t: Time<UT>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<GPS>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<JD>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<JDE>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<MJD>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<TAI>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<TCB>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<TCG>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<TDB>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<TT>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

impl From<Time<UnixTime>> for Time<UT>

fn from(t: Time<UnixTime>) -> Self

Converts to this type from the input type.

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

fn eq(&self, other: &Time<S>) -> 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<S: PartialOrd + TimeScale> PartialOrd for Time<S>

fn partial_cmp(&self, other: &Time<S>) -> 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<S: TimeScale> Sub<Quantity<Day>> for Time<S>

type Output = Time<S>

The resulting type after applying the - operator.

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

Performs the - operation.

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

type Output = Quantity<Day>

The resulting type after applying the - operator.

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

Performs the - operation.

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

fn sub_assign(&mut self, rhs: Days)

Performs the -= operation.

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

type Duration = Quantity<Day>

The duration type used for arithmetic operations.

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

Convert this time instant to UTC DateTime.

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

Create a time instant from UTC DateTime.

fn difference(&self, other: &Self) -> Self::Duration

Compute the difference between two time instants.

fn add_duration(&self, duration: Self::Duration) -> Self

Add a duration to this time instant.

fn sub_duration(&self, duration: Self::Duration) -> Self

Subtract a duration from this time instant.

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

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