Cast a synastry chart

Enter both people’s birth date, time and place. The tool casts a chart for each, then computes house overlays, inter-aspects with orbs, plus composite and Davison charts. Say what you most want to see clearly.

What kind of relationship is this?

Set this first: it decides which houses the reading looks at and how the five themes are ordered.

The type never enters the numbers: switching it leaves every aspect and placement identical. Now: No relationship type assumed; read the overall interaction first

What do you most want to see clearly?

Pick the closest one, or write it in your own words. Once the chart is cast, the reading answers it against both charts.

A

Person A

Synastry casts one natal chart per person, then reads the relationship between them. Order only decides which side is which.

Birth details · Person A

The Ascendant and houses come from the birth instant plus coordinates: 4 minutes of clock error moves the Ascendant about 1°

Linked timezone Asia/Shanghai · Longitude 116.4074° · Latitude 39.9075°

Astrology restores the UT instant from the recorded clock time (including historical offsets and DST), then uses latitude and longitude for the Ascendant and houses. Accuracy matters: the Ascendant moves about 1° every 4 minutes.

B

Person B

Birth details · Person B

The Ascendant and houses come from the birth instant plus coordinates: 4 minutes of clock error moves the Ascendant about 1°

Linked timezone Asia/Shanghai · Longitude 116.4074° · Latitude 39.9075°

Astrology restores the UT instant from the recorded clock time (including historical offsets and DST), then uses latitude and longitude for the Ascendant and houses. Accuracy matters: the Ascendant moves about 1° every 4 minutes.

Fill in both birth details first

Names are used for the chart title only and never enter the calculation; birth details stay in the link and are not stored on the server.