Astronomical space coordinate and time conversion. Calculate Julian day, local sidereal time and ecliptic obliquity with great precision.

A Swift framework containing an astronomical model of the Moon, including properties to obtain the age, percent illuminated, phase, transitions, and other properties of the Moon at a point in time. This is a Swift port of John Walker's `moontool.c`, originally written in 1987.

Julian date calculations and calendar conversions for Swift