natal-chart

A chart computed from the wrong time is specific numbers all the way down, with nothing on its face to show what is wrong.

What it produces

Thirteen bodies with sign, degree, house, retrograde state and classical dignity; the four angles and the derived points; the intra-chart aspects, each pair recorded once; the sect, decided by the sun's position; and the six classical lots, whose formulae are chosen by that sect.

Classical rulerships only

Modern rulerships — Uranus for Aquarius, Neptune for Pisces — are not written into the output. Stating them as fact settles a disagreement between traditions on their behalf, and the value of this calculation is that it emits only the part every tradition agrees on.

Without ephemeris data it refuses

It does not run without ephemeris data unless you explicitly choose the built-in analytic ephemeris, and that downgrade is recorded in the artefact's limitations, because two charts of different precision should not look alike.

What it does not do

It computes; it does not interpret. No two-person synastry, no transits, progressions or returns, and no dated prediction of any kind. Interpreting a chart that already exists is natal-reading.