Crate hifitime

hifitime 0.0.1

Precise date and time handling in Rust built on top of std::time::Duration. 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
• UTC representation with ISO8601 formatting (and parsing in that format)
• Allows building custom TimeSystem (e.g. Julian days)
• Simple to use Offsets to represent fixed or time-varying UTC offsets (e.g. for very high speed reference frames)
• Clock drift via oscillator stability for simulation of time measuring hardware (via the simulation feature)

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.

Does not include

• Dates only, or times only (i.e. handles only the combination of both), but the Datetime::{at_midnight, at_noon} help
• Custom formatting of date time objects
• An initializer from machine time

Usage

Put this in your Cargo.toml:

[dependencies]
hifitime = "0.1.0"

And add the following to your crate root:

extern crate hifitime;

Examples:

use hifitime::datetime::{Datetime, TimeSystem};
use hifitime::instant::Duration;
use hifitime::julian::ModifiedJulian;

let santa = Datetime::new(2017, 12, 25, 01, 02, 14, 0).expect("Xmas failed");

assert_eq!(
    santa.into_instant() + Duration::new(3600, 0),
    Datetime::new(2017, 12, 25, 02, 02, 14, 0)
        .expect("Xmas failed")
        .into_instant(),
    "Could not add one hour to Christmas"
);
assert_eq!(format!("{}", santa), "2017-12-25T01:02:14+00:00");
assert_eq!(
    ModifiedJulian::from_instant(santa.into_instant()).days,
    58112.043217592596
);
assert_eq!(
    ModifiedJulian::from_instant(santa.into_instant()).julian_days(),
    2458112.5432175924
);

Modules

datetime	The datetime module supports conversions between seconds past TAI epoch and a Datetime struct. The main advantage (and challenge) is the inherent support for leap seconds. Refer to module documentation for leap second implementation details.
durations	The durations module provides helpers for initializing an std::time::Duration.
instant	The instant module is built on top of std::time::Duration. It is the basis of almost all computations in this library. It is the only common denominator allowing for conversions between Time Systems.
julian	The julian module supports (Modified) Julian Days, which are heavily used in astronomy and its engineering friends.

Enums

Errors

Errors handles all oddities which may occur in this library.

Traits

TimeSystem

A TimeSystem enables the creation of system for measuring spans of time, such as UTC or Julian days.