What is the practical result of the original constellation boundaries being set based on positions from two thousand years ago?

The commonly associated dates rarely match the actual celestial territory the Sun occupies

The consequence of establishing constellation boundaries based on the alignment of two millennia ago, combined with the ongoing precession of the equinoxes, is a significant divergence between traditional calendrical markers and current astronomical reality. While a calendar might state that the Sun is in Aries between specific dates, the actual stellar grouping currently lying along the ecliptic during those same dates is likely a different constellation, such as Pisces, or partially overlapping territories. This means the popular association of a specific date range with an astrological sign functions more as a historical calendrical convention rather than an accurate, up-to-the-minute observation of where the Sun is physically located among the actual, modernly defined constellation boundaries.