Short explainer
Birth data, private by design
Read the transcript
A chart needs your birth date, exact time, and place. It does not need an account or a permanent record. AstralMath runs the calculation on your device, so the inputs stay with you.
Is it safe to upload my birth time and place to an astrology app?
Visual explainer
The minimum-data path
On your device
Inputs → local engine → chart
DateTimePlace
Not required by the maths
Name · email · contacts · account · cloud history
12 sec
What's actually true — the astronomy
The calculation genuinely needs an instant and location: time establishes the Earth’s rotation and planetary positions, while latitude and longitude establish the local horizon. It does not mathematically require an email address, profile, cloud history or permanent record. Local WebAssembly can perform the same ephemeris and house calculations without sending the birth inputs to a calculation server.
What the tradition says (interpretation)
Astrological practice often treats a natal chart as intimate because it is used to discuss relationships, health, family and life history. Whether or not you accept those interpretations, the underlying date and place can still help identify a real person. The privacy issue belongs to the data flow, not to the belief system.
The decision-science move — what to actually do
Before entering birth data, check four things: does the calculator work without an account; does its privacy policy say whether the raw inputs or generated chart are stored; can you delete any saved data; and does the calculation still work with the network disabled after the app loads? For a public post, assume the chart wheel itself may reveal the date. Share only what you are comfortable making durable.
Why this question is here
People are working this out in public right now
These current discussions surfaced the question. They are community signals, not evidence for the answer; the technical and research sources are listed separately below.
References
- [1]Guide to Protecting the Confidentiality of Personally Identifiable Information — NIST Special Publication 800-122NIST includes date and place of birth among information that can distinguish or trace an individual when linked with other data.
- [2]Swiss Ephemeris — Astrodienst AGThe high-precision ephemeris AstralMath compiles to WebAssembly and runs unmodified.
More questions like this in the decision-science library, or read how we separate the math from the myth.