In astrology, Chart Rectification is the process of estimating or refining a birth time when the recorded time is missing, uncertain, or considered inaccurate. An astrologer may compare different possible Ascendants, house cusps, chart angles, planetary positions, and timing techniques with documented life events, personal characteristics, and other biographical information. Methods vary widely and may include transits, progressions, directions, profections, or other timing systems. Because rectification depends on interpretation, incomplete records, and methodological judgment, the resulting birth time should generally be treated as an informed estimate rather than as a proven historical fact.