Astrology Explained — All the Sigastra Tools

Astrology explained: how these tools fit together

Astrology terms — the elements, the modalities, degrees, houses and aspects — are all explained in the Learn guides, and everything listed above comes from one calculation. Give a date, a time and a place and the 高精度な天体暦 returns where every body in the solar system sat, seen from that spot, at that instant — corrected for the time zone that was actually in force there that year, which is not always the one in use today. Every tool on this page is a different question asked of that one set of positions.

The three layers, from slowest to fastest

The birth chart is the still frame: where things were when you began, and it never changes. The return charts — solar, lunar, progressed — recast that same moment forward, asking what the sky looks like now against the sky you started with. The horoscopes are the fast layer: the daily reads the Moon, which changes sign every two and a half days, the weekly reads the Moon’s phase, the monthly reads the Sun, and the yearly reads Jupiter and Saturn. They do not contradict each other; they are different zoom levels on the same sky.

Which of these needs your birth time

This is the question that decides what is worth using. The Rising sign moves a full degree every four minutes, so anything built on it — the Rising sign calculator, the houses in a natal chart, a solar or lunar return — is only as good as the time you put in. Sun sign, Moon sign for most of a day, planetary positions and compatibility by sign all work from a date alone. Where a time is missing, the honest answer is to say which half of the reading still stands rather than to compute both and present them alike.

Free, Plus and Pro — where the line falls

The line is not drawn at the astronomy. Every position on this site is computed the same way whichever tier you are on, and the full birth chart, the daily horoscope and the compatibility overview are free with no account required. What the paid tiers add is depth of interpretation and the relationship charts — synastry, composite, the return charts and the full house-by-house natal reading. If a tool is listed above without a tier badge, it is free.