Function jday_internal 

pub fn jday_internal(
    year: f64,
    mon: f64,
    day: f64,
    hr: f64,
    min: f64,
    sec: f64,
    msec: Option<f64>,
) -> f64

procedure jday

this procedure finds the julian date given the year, month, day, and time. the julian date is defined by each elapsed day since noon, jan 1, 4713 bc.

algorithm calculate the answer in one step for efficiency

author david vallado 719-573-2600 1 mar 2001

Parameters

• year: year
• mon: month
• day: day
• hr: hour
• min: minute
• sec: seconds
• msec: milliseconds

Returns

Julian date