Local LLMs fail 18th-century calendar test

This "tricky question" serves as a sharp reminder that benchmark scores often mask fundamental reasoning failures in smaller models. Consumer-grade models running on hardware like 64GB Macs frequently fail to connect the 1752 calendar shift to specific date calculations, with failure modes ranging from "medical miracles" to circular reasoning. The gap highlights the difference between a model knowing a fact and reasoning with it, as even high-performing open-weight models like Qwen struggle when historical context overrides modern defaults.