hifitime 1.0
Precise date and time handling in Rust built on top of std::f64
.
The Epoch used is TAI Epoch of 01 Jan 1900 at midnight, but that should not matter in
day-to-day use of this library.
Features
- Leap seconds (as announced by the IETF on a yearly basis)
- Julian dates and Modified Julian dates
- Clock drift via oscillator stability for simulation of time measuring hardware (via the
simulation
feature) - TODO: UTC representation with ISO8601 formatting (and parsing in that format #45)
- Support for custom representations of time (e.g. NASA GMAT Modified Julian Date)
- Trivial support of other time representations, such as TDT (cf #44)
Almost all examples are validated with external references, as detailed on a test-by-test basis.
Leap second support
Each time computing library may decide when the extra leap second exists as explained
in the IETF leap second reference.
To ease computation, hifitime
decides that second is the 60th of a UTC date, if such exists.
Note that this second exists at a different time than defined on NASA HEASARC. That tool is
used for validation of Julian dates. As an example of how this is handled, check the Julian
day computations for 2015-06-30 23:59:59,
2015-06-30 23:59:60 and 2015-07-01 00:00:00.
Changelog
version 1.0 - COMPLETE rewrite
The previous API is totally incompatible with version 1.0.
In this new version:
- Correct and explicit support for TAI versus UTC (previously, UTC was implied in the
Datetime
struct and TAI was implied in theInstant
struct) - Removed annoyingly high precision which prevented simple day-to-day operations on seconds (as needed in most time simulation software)
Motivation
After using this extensively for a few months, I've come to realize that it was highly ambiguous, and frankly a pain in the neck to use because of the complexity of the Instant
struct. It made common operations complicated for no good reason. And at least one major bug existed (the difference between two Instant
of MJD was different from the actual difference of MJDs converted to seconds).