Why a recorded birth time may be rounded
During a delivery, the immediate priority is caring for the parent and newborn, not producing a timestamp precise to the minute. A birth time may be entered or recalled later, and a record may give a time rounded to the nearest five or 10 minutes. That does not mean every hospital or nurse follows the same practice; it means the written time can be less exact than it appears.
What that can change in an astrology chart
Astrology charts use the birth time, along with the date and place, to calculate features such as the ascendant—the zodiac sign said to be rising on the eastern horizon at birth—and the chart’s houses, which divide the sky into life-related areas. Because the sky’s apparent position changes continuously, a shift of several minutes can alter those calculations, especially near a boundary between signs or houses.
The effect depends on the chart and how close its calculated positions are to such a boundary. A rounded time is therefore not automatically useless, but it may not support claims of minute-level precision. If a chart changes substantially across a few plausible birth times, that uncertainty comes from the timestamp itself, not from a difference in the person’s birth.
