C and D data tend to change when AstroDatabank data are upgraded. Since data are always volatile, no rating system is infallible and data are often updated when new information comes to light. Accuracy and Rodden Ratings AA, A, and B data are the only data that should be used in astrological studies. Politicians and entertainers are notorious for giving misleading birth dates and times, except when consulting their astrologer. In all cases where there is no source or data classification, the data can only be considered hypothetical.
Some astrologers consider rectified times more accurate than birth times.
Unfortunately, there is no consensus on how to rectify birth times. Until there is a standard and proven rectification method, you should treat all rectified data with caution. However, over the years, many astrologers have contributed anonymous data from their collections that come from first-hand knowledge of the case history. They give a birth time to the minute along with dates of events in the medical history or trauma that is being discussed. One of the birth times may be right, but more research is required to determine which one.