Page "Natal chart" Paragraph 16

If the birth time cannot be obtained, or is not precise, some astrologers try to find it by rectification.

This is usually done by making a list of important events in the person's life, and calculating what birth time would give the most appropriate progressions and / or transits for these dates.

Another method, often combined with the former, is to decide what birth time would give a chart that seems to describe the person most accurately-especially as regards physical appearance.

Not all astrologers approve of rectification, however.