How ChartLune works
Accuracy and privacy are the two things most free chart sites get wrong. Here's how we handle both.
Real ephemeris positions
Every planet's position is calculated from the Moshier ephemeris — the same astronomical lineage as the Swiss Ephemeris that professional astrologers rely on. This is genuine astronomy, not a lookup table of approximate sign dates, so placements are accurate to the degree.
Correct historical timezones
Your Ascendant and house cusps depend entirely on the exact moment and place of birth. We resolve the historical timezone — including the daylight-saving rules that applied on your specific birth date — from your birth city's coordinates. This is the step that cheaper calculators skip, and it's why their rising signs are often wrong.
Calculated in your browser
The entire computation runs as JavaScript on your own device. Your birth date, time and location are never transmitted to or stored on a server. The only network request is an anonymous city lookup so we can find your birth coordinates.