Crate tempoch_core 

Typed astronomical time primitives.

The central type is Time<S>, where S is a Scale marker (TT, TAI, UTC, UT1, TDB, TCG, TCB).

tempoch makes a few explicit modeling decisions:

• Time<S> is an instant on a scale-specific axis, not a bare scalar.
• Time arithmetic follows affine rules: instant minus instant yields a duration; shifting an instant by a duration yields another instant.
• Internal storage is a compensated (hi, lo) pair of J2000-based seconds so large epoch values can retain small corrections and sub-second detail.
• JD, MJD, J2000s, Unix, and GPS are conversion targets, not independent storage models.
• UTC keeps special civil semantics: it is stored as a continuous instant and interpreted through the active UTC-TAI table when civil labels are needed.

The old format-generic storage model has been replaced with explicit constructors and accessors:

• built-in coordinate scales expose J2000-second, JD, and MJD constructors/accessors
• UTC exposes both raw instant-axis helpers and civil/transport APIs (chrono, POSIX)
• TAI exposes GPS transport helpers
• unified conversion targets are available through time.to::<Target>(), time.try_to::<Target>(), and time.to_with::<Target>(&ctx)

See constats for typed epoch and offset constants.

Re-exports

pub use constats::GPS_EPOCH_JD_TAI;

pub use constats::GPS_EPOCH_JD_UTC;

pub use constats::GPS_EPOCH_TAI_MINUS_UTC;

pub use constats::UTC_DEFINED_FROM_MJD;

pub use error::ConversionError;

pub use error::TimeDataError;

pub use ext::TimeInstant;

pub use representation::EncodedTime;

pub use representation::GpsTime;

pub use representation::InfallibleRepresentationForScale;

pub use representation::J2000Seconds;

pub use representation::J2000s;

pub use representation::JulianDate;

pub use representation::ModifiedJulianDate;

pub use representation::RepresentationForScale;

pub use representation::TimeRepresentation;

pub use representation::Unix;

pub use representation::UnixTime;

pub use representation::GPS;

pub use representation::J2000_TT;

pub use representation::JD;

pub use representation::JULIAN_YEAR_DAYS;

pub use representation::MJD;

pub use scalar::scalar_add_days;

pub use scalar::scalar_difference_in_days;

pub use scalar::time_tt_from_scalar;

pub use scalar::time_tt_to_scalar;

pub use scalar::ScaleKind;

Modules

constats

Typed epoch and offset constants.

eop

Daily IERS Earth Orientation Parameters from the compiled finals2000A.all series.

error

ext

Extension traits for time types.

representation

Typed encoded representations of crate::Time.

scalar

Scalar-value adapter for time scale dispatch.

Structs

Interval

Half-open time interval [start, end).

TAI

International Atomic Time. Continuous SI-second clock.

TCB

Barycentric Coordinate Time (IAU 2006 B3). Linear relation to TDB.

TCG

Geocentric Coordinate Time (IAU 2000 B1.9). Linear rate difference to TT.

TDB

Barycentric Dynamical Time.

TT

Terrestrial Time. The dynamical reference scale in this crate.

Time

A point in time on scale S.

TimeContext

Explicit, immutable context for conversions that need one.

UT1

Universal Time 1 — Earth-rotation time axis.

UTC

Coordinated Universal Time.

Enums

InvalidIntervalError

Error constructing an Interval with invalid bounds.

PeriodListError

Invariants on a period list.

Constants

DELTA_T_PREDICTION_HORIZON_MJD

MJD of the last compiled ΔT prediction point.

EOP_END_MJD

EOP_OBSERVED_END_MJD

EOP_START_MJD

MODERN_DELTA_T_OBSERVED_END_MJD

Traits

ContextConversionTarget

Unified context-backed conversion target for Time<S>::to_with::<T>(&ctx).

ContinuousScale

Witness that a scale is both coordinate-bearing and physically continuous.

ConversionTarget

Unified conversion target for Time<S>::try_to::<T>().

CoordinateScale

Witness that a scale is continuous and supports direct arithmetic. UTC deliberately does not implement this: it has raw-axis accessors through CoordinateScale, but its civil interpretation remains leap-second-aware and table-driven.

InfallibleConversionTarget

Unified infallible conversion target for Time<S>::to::<T>().

Scale

Marker trait for a scientifically distinct time scale.

Functions

complement_within

Gaps inside outer that are not covered by any interval in periods.

delta_t_seconds

ΔT = TT − UT1, in seconds, for a Julian Day on the UT1 axis.

delta_t_seconds_extrapolated

ΔT = TT − UT1, in seconds, with quadratic tail-fit extrapolation beyond the last published prediction point.

Type Aliases

InvalidPeriodError

Backward-compatible alias for period construction validation errors.

Period

Typed time period on a given scale.