🕸️ Bi-Temporal Knowledge Graphs

The Challenge of Evolving Facts

In naive vector stores, if a user states:

• 2024: “I prefer Neovim over VSCode.”
• 2026: “I switched to Foot terminal and Antigravity.”

A standard vector query retrieves both, creating hallucinations and conflicting instructions.

Bi-Temporal Dimensions

A bi-temporal graph associates every edge with two time horizons:

1. Assertion Time (valid_at -> invalidated_at): When the fact was true in the real world.
2. System Time (recorded_at -> archived_at): When the knowledge base learned the fact.

Obsidian Interoperability

In Obsidian_Vault, bi-temporal facts are rendered using YAML frontmatter properties (valid_from, valid_until) and wikilink relation syntax, enabling historical timeline queries using Dataview.