Composite Chart Calculator

A composite chart is the set of midpoints between two birth charts, and this works every one of them out from the two births. Enter both dates, times, UTC offsets and birthplaces and it returns the composite Sun through Pluto, the mean node, both of the rival derivations of the composite ascendant, the midheaven, the aspects that fall inside the composite itself and the element and modality balance. A second action builds the Davison chart instead, which is a real chart cast for the instant halfway between the two births at the point halfway between the two birthplaces, so its Moon and its angles are computed rather than averaged. The positions come from the same ephemeris the synastry page uses and are good to a few arcminutes over 1900 to 2049. Astrology is entertainment, and the arithmetic here is astronomy rather than a reading.