Clock time is not the whole input
Legal time zones apply one clock across a wide region, while solar position varies by longitude. Birthplace, historical time-zone rules and daylight saving can therefore affect the hour pillar near a boundary.
What true solar time means
True solar time adjusts standard clock time for longitude and the sun’s apparent movement. Traditions differ on whether and how to use it, so reports should preserve the original record and state the chosen method.
Cases requiring extra care
Check locations far from the central meridian, historical time-zone changes, daylight saving, approximate family memories and births near two-hour boundaries. Midnight and solar-term boundaries may affect other pillars as well.
When the time is unknown
Analyse the stable year, month and day pillars while clearly marking the hour as unknown. Limited rectification may compare plausible hours, but it should not select the most attractive chart.
Data-submission standard
Record date, exact documented time, city and country, plus whether the source is a certificate, hospital record or family memory. Preserve calculation settings and uncertainty in the final report.