Unknown birth time does not make all astrology impossible, but it changes the confidence level. Planetary signs are often stable across a day; the Moon may change sign; houses and angles depend directly on time.
Use a noon chart transparently
A noon chart gives a neutral reference for planetary positions. It must be labeled clearly, and house or angle interpretations should be omitted rather than presented as precise.
Check the Moon’s daily range
Calculate the Moon near the start and end of the date. If it crosses a sign boundary, both possibilities should remain open until better evidence appears.
Treat rectification as inference
Rectification compares candidate times against dated life events and chart techniques. It can narrow hypotheses but should not be marketed as certainty produced from personality questions alone.
Insight becomes useful when it changes a question, observation, boundary, conversation, or action you can test.