Large language models compress centuries of discourse into fixed parameters, yet how they organize historical variation and whether this organization shapes generation remain unclear. We introduce the Time Travel Engine (TTE), a framework that compares geometric accounts of era-conditioned residual states and tests their behavioral accessibility under fixed prompts. Across six decoder language models in Chinese and English, broad eras repeatedly form ordered trajectories, although their exact spacing varies across model–language settings. Steering along these trajectories shifts both historical register and access to period-compatible knowledge, while adjacent anchors support local interpolation. Epistemic effects partly survive style removal, linking temporal steering to knowledge access beyond surface register. Across Chinese and English, partially alignable trajectories reveal corresponding chronological relations whose geometric realization remains language-specific. Together, ordered temporal geometry offers a testable account of how static language models organize diachronic variation, linking internal structure to historical register and access to period-compatible knowledge. Code and datasets: https://github.com/LilTiger/Time-Travel-Engine.