Variable‐Length Ultra‐Scale Time Segmented Coding Model: Applications to Deep‐Time Digital Earth

Time underpins analysis across the natural and social sciences, yet representing and computing it across extreme temporal scales and multiform expressions remains challenging, particularly in cross‐disciplinary data integration and discovery in the geosciences. Textual forms are difficult to compute, numerical forms often suffer from unit inconsistencies and symbolic complexity, and existing temporal models remain limited in cross‐scale continuity and flexibility. To address these issues, this study conducts a systematic analysis of the distinct characteristics of time and proposes a novel time‐coding framework—Variable‐length Ultra‐scale Time Segmented Coding (VUTSC). This method encodes time as three components: a Base reference, a Level indicator, and a variable‐length sequence of Codes, which together enable consistent and scalable representation across ultra‐wide temporal scales within a unified structural framework. Using the geosciences as a case study, we build a Deep‐Time Digital Earth Timeline System based on VUTSC. Experiments on multi‐scale and interdisciplinary time expressions validate the feasibility, breadth, simplicity, flexibility, and efficiency of VUTSC. Results indicate that this model can effectively express geoscientific time across a wide range of scales, while its coding efficiency is significantly higher than that of timestamp‐based methods. The encoding and decoding strategies are stable and support hierarchical traversal, neighborhood search, and time‐relationship calculations. For time‐centric scientific disciplines, including the Earth sciences, this approach provides a promising pathway for multi‐source, multi‐scale data mining and knowledge discovery.