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Wakusei Planets惑星

The Sun, the planets and their moons as a clean line drawing, a shaded realistic drawing or a painted surface map, with real sizes, tilt and rotation, and the moons where they are at any date and time.

Wakusei is the Japanese word 惑星 for a planet. About the name

Contents

Reference · Julian dates (and the julian package's functions), calendars, time scales, sidereal time and Mars time

julianCenturiesfunction

Julian centuries (36,525 days) from J2000.0: the time argument of most theories. In terrestrial time unless scale says UTC.

Import it

import { julianCenturies } from "@johnmorrisdotca/wakusei-planets/time";

Definition

function julianCenturies(when: When, scale?: "tt" | "utc"): number

Parameters

NameTypeDescription
whenWhen

A Date or milliseconds since 1970 (UTC).

scale (optional)"tt" | "utc"

"tt" (the default, what the theories want) or "utc" to count the clock's days.

Returns

number

Julian centuries, negative before 2000.

Examples

import { julianCenturies } from "@johnmorrisdotca/wakusei-planets/time";

console.log(julianCenturies(Date.UTC(2100, 0, 1, 12)).toFixed(6));
1.000000

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/wakusei-planets 0.24.0.