How to read the two rings
The inner brown markers show natal tropical planets. The outer blue markers show draconic longitudes for the same planets. Both rings use the fixed zodiac labels around the edge, so you can compare signs and degrees directly. Hover or focus on a marker to identify it; the table gives every position in text.
Choosing the mean or true North Node changes the rotation angle. Near a sign boundary, that may change a draconic sign. The planetary angular distances within each ring are identical because every point moves by the same amount. A planet's natal house also remains the same when the house cusps are rotated with it.
Calculation and limits
For each point, draconic longitude = (tropical longitude − selected tropical North Node longitude) modulo 360°. The selected draconic North Node therefore lands at 0° Aries. This page uses Astronomy Engine 2.1.19 for apparent geocentric tropical planet longitudes; the true node comes from the instantaneous lunar orbital plane and the mean node from a Meeus polynomial. Planet positions use the true ecliptic and equinox of date; the mean-node polynomial is stated in the mean frame, so small differences from other ephemerides are possible.
With an unknown birth time, the calculator samples 12:00 local time on the supplied date and cannot establish Ascendant, Midheaven, or houses. The Moon and lunar node may move enough to change a displayed degree or a nearby sign. At a geographic pole, angles may remain undefined even with a recorded time. Draconic signs are symbolic coordinates, not another observation of the sky, and astrological interpretation cannot establish personal traits or events.