`get-bodygraph-json.js` returns the wrong design time

[vhpoet]

Design Time Falls Outside Loaded Ephemeris Year

Description

The Design time calculation in the Human Design logic incorrectly selects a date outside the expected ~88–89 day prenatal window because the ephemeris data is loaded for only a single year (the birth year). When the Design time falls in the prior year (e.g., late December of the previous year for an early-year birth), the search continues forward and matches a later occurrence of the Sun’s position within the loaded year, resulting in an incorrect Design time and misaligned planetary positions.

Steps to Reproduce

1. Use a birth date early in a year (e.g., March).
2. Load ephemeris data for only that year.
3. Calculate the Design time and log the result.

Expected Behavior

• Design time should be ~88–89 days before the birth date, potentially in the prior year.
• All planetary positions align with that prenatal period.

Actual Behavior

• Design time matches a date in the loaded year, often months after the birth date, due to the absence of prior-year data.

Root Cause

• Only one year of ephemeris data is loaded, excluding the prior year where the Design time may reside.
• The search isn’t constrained to the correct prenatal window, allowing it to overshoot.

Suggested Fix

• Load ephemeris data for both the birth year and the previous year.
• Constrain the Design time search to a window of 87–90 days before the birth date.
• Alternatively, adopt a multi-year ephemeris solution like Swiss Ephemeris.