geodate 0.5.0

Geodate computes geocentric expressions of points in time using a natural lunisolar calendar with metric time based on decimal fractions of the mean solar day.
Documentation 
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#[cfg(not(feature = "std"))]
use num_traits::Float;

pub const J2000: f64 = 2451_545.0; // TODO: Add 0.0009 to this value?

pub fn unix_to_julian(timestamp: i64) -> f64 {
    (timestamp as f64 / 86400.0) + 2440587.5
}

pub fn julian_to_unix(jd: f64) -> i64 {
    ((jd - 2440587.5) * 86400.0).round() as i64
}

// Returns the Julian year for a given Julian ephemeris day
pub fn jde_to_julian_year(jde: f64) -> f64 {
    2000.0 + (jde - J2000) / 365.25
}

pub fn jde_to_julian_century(jde: f64) -> f64 {
    (jde - J2000) / 36525.0
}

pub fn jde_to_julian_millenia(jde: f64) -> f64 {
    (jde - J2000) / 365250.0
}

pub fn unix_to_year(timestamp: i64) -> f64 {
    1970.0 + (timestamp as f64) / 86400.0 / 365.25
}

#[cfg(test)]
mod tests {
    use super::*;
    use utils::*;

    #[test]
    fn jde_to_julian_millenia_test() {
        assert_approx_eq!(-0.007_218_343_600, jde_to_julian_millenia(2448908.5), 0.000000000001);
    }

    #[test]
    fn unix_to_year_test() {
        assert_approx_eq!(1970.99, unix_to_year(parse_time("1970-12-31T23:59:59+00:00")), 0.01);
        assert_approx_eq!(1971.00, unix_to_year(parse_time("1971-01-01T00:00:00+00:00")), 0.01);
    }
}