The BaZi month is seasonal
BaZi month pillars are tied to solar terms, not simply calendar months. This matters because the Month Pillar carries seasonal strength.
Boundary births need care
If someone is born near a solar-term boundary, the month pillar may differ from what a normal calendar assumption suggests. That can affect the Day Master reading.
Why this improves trust
A calculator that explains solar terms gives users a clearer reason for the result. It also avoids overconfidence when a birth date is close to a boundary.