Precise and Consistent Lunar Return Calculation
The Lunar Return calculation infrastructure of the Numji Astrology Engine was comprehensively tested across 250 test cases spanning the 1958–2100 period, generated from various birth and return locations. A total of 5,045 checks were performed, ranging from the exact return moment of the natal Moon longitude to houses, celestial bodies, and Lunar Return–Natal aspects.
The natal Moon longitude, number and sequence of returns within the month, exact return time, return chart houses, celestial bodies, and major aspects formed with the natal chart were found to be fully consistent with expected outcomes across all test cases.
Validated Lunar Return calculations
The primary result groups forming the time, location, house, and aspect foundation of the Moon return chart.
EXACT MOON RETURN MOMENT
The UTC and local return time when the transiting Moon returns to the natal Moon's exact longitude were checked using an independent hourly scan and root refinement method.
RETURN COUNT AND SEQUENCE
All Moon returns within the selected local month were scanned independently; the return count, chronological order, and first or second occurrence selection were validated.
HOUSES AND CELESTIAL BODY PLACEMENTS
Placidus houses and the longitudes, motion directions, and house placements of the 10 primary celestial bodies in the return and natal charts were directly recalculated.
LUNAR RETURN–NATAL ASPECTS
Conjunctions, sextiles, squares, trines, and oppositions between the return chart and the natal chart were independently reproduced along with target aspect and orb values.
Validation results
Success distribution of control groups applied across 250 cases.
| Control Group | Checks | Compatible | Failed | Result |
|---|---|---|---|---|
| Request info, UTC, and local time | 1,500 | 1,500 | 0 | Passed |
| Return detection, sequence, and Moon longitude | 2,033 | 2,033 | 0 | Passed |
| Houses and celestial body placements | 750 | 750 | 0 | Passed |
| Major aspects, orb, and deterministic result | 750 | 750 | 0 | Passed |
| Invalid input protections | 12 | 12 | 0 | Passed |
| Total | 5,045 | 5,045 | 0 | Passed |
Highlighted precision and consistency results
Evaluation of the Moon return moment and its dependent results against acceptance criteria.
| Metric | Applied Criterion | Observed Result | Result |
|---|---|---|---|
| Natal–return Moon longitude difference | Maximum 0.0002° | All cases within limit | Passed |
| Independent return time comparison | Maximum 0.001 seconds | All cases within limit | Passed |
| Return list and sequence selection | Exact count and chronology | Exact match | Passed |
| Houses, celestial bodies, and aspects | Direct recalculation | Exact match | Passed |
| Repeated calculation | Same result for identical input | Deterministic | Passed |
Test methodology
Time, geography, and calculation diversity were handled together to ensure the result is not tied to a single birth date or return location.
SCOPE
- Return years: 1958–2100
- 250 distinct Lunar Return cases
- A wide range of birth dates and return months
- Total of 5,045 validation checks
TIME AND LOCATION
- UTC and local time conversion
- UTC offsets between -10 and +12 hours
- Northern and Southern hemisphere samples
- Return locations different from the birthplace
INDEPENDENT ROOT SCANNING
The selected local month was scanned with one-hour steps, separate from the engine's two-hour search. Each detected transition was further refined using binary search and compared against the engine's return list.
DEFENSIVE VALIDATION
Invalid years, months, sequences, coordinates, GMT, and orb values along with NaN inputs were tested; it was verified that the engine rejects these values before computations begin.
What does this result mean for the astrologer?
The return moment, local time, houses, celestial body degrees, and natal contacts upon which Lunar Return interpretation relies are presented with a calculation chain that works consistently across different dates and geographies. This ensures that the astrologer can be confident that the correct return within the month has been selected, allowing them to focus on interpreting the roughly 27-day theme of the chart rather than technical calculations.