Temporal Tokenization Strategies for Event Sequence Modeling with Large Language Models
Paper · 2026 · Zefang Liu, Nam H Nguyen, Yinzhu Quan et al.
Summary
LLMs process discrete tokens, but events in real sequences happen in continuous time. How to turn timestamps or inter-event gaps into tokens ("temporal tokenization") has received little systematic study. This paper compares five families of encodings: plain numeric strings, float32 byte tokens (as in Language-TPP), Gregorian calendar tokens, uniform scale binning in linear or log space, and a new residual scalar quantization (RSQ) scheme. RSQ stacks K-Means codebooks over successive residuals.
Each variant is fine-tuned on Llama-3.2-1B with QLoRA. The data are five public TPP-LLM benchmarks whose interval distributions range from smooth log-normal to multi-modal to sharply spiky. Next-event-type accuracy barely changes across tokenizers, but time-prediction error depends strongly on how well the encoding fits the data's distribution.
The study offers practical guidance on choosing a time encoding. It also shows that plain next-token fine-tuning, with no TPP heads or likelihood integrals, is a simpler and competitive alternative to hybrid point-process models.
Key points
- Data: five TPP-LLM datasets (hosted on Hugging Face under
tppllm), covering Amazon Review, US Earthquake, NYC Taxi, Chicago Crime and Stack Overflow. They range from about 30K to about 362K events. - Configurations and cost:
- Numeric strings use 6 decimals and take roughly 4 tokens.
- Byte encoding always uses 4 tokens.
- Calendar tokens come in day and second resolution, absolute or relative, using 3 or 6 tokens.
- Scale binning uses 256 bins and a single token.
- RSQ uses either 1 level of 256 bins or 4 levels of 64 bins.
- Evaluation: metrics are next-type accuracy, interval RMSE and tokens per time value. Results are averaged over 5 seeds.
- Best time-prediction strategy by dataset:
- Log-scale strategies win on Stack Overflow, Chicago Crime and Amazon Review: Scale Bin (Log) on Chicago Crime, and RSQ (Log, L4) on the other two.
- Absolute Calendar (Second) wins on NYC Taxi, since it captures daily and hourly cycles.
- Byte wins on US Earthquake.
- Efficiency: single-token log binning and RSQ offer the best balance between accuracy and token cost. Code is available at github.com/CapitalOne-Research/temporal-tokenization.
Institutions
Fields, topics and concepts
📚 Shelves 5The field of science this work belongs to (OpenAlex fields).Computer Science · 16,667 worksArtificial Intelligence · 16,194 worksArts and Humanities · 16,039 worksLanguage and Linguistics · 15,891 worksSignal Processing · 452 works
🧭 Topics 1Research subjects and languages the work is about.Tokenization & segmentation · 119 works
Cite
Cite as Zefang Liu, Nam H Nguyen, Yinzhu Quan and Shi-Xiong Zhang. 2026. Temporal Tokenization Strategies for Event Sequence Modeling with Large Language Models. Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM).
@inproceedings{liu2026temporal,
title = {{Temporal Tokenization Strategies for Event Sequence Modeling with Large Language Models}},
author = {Zefang Liu, Nam H Nguyen, Yinzhu Quan and Shi-Xiong Zhang},
booktitle = {Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM)},
year = {2026},
doi = {10.18653/v1/2026.gem-main.5},
url = {https://doi.org/10.18653/v1/2026.gem-main.5}
}References
- Gagan Bhatia, Maxime Peyrard, and Wei Zhao. 2025. Date fragments: A hidden bottleneck of tokenization for temporal reasoning. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 3201–3219, Suzhou, China. Association for Computational Linguistics. find
- Tim Dettmers, Artidoro Pagnoni, Ari Holtzman, and Luke Zettlemoyer. 2023. QLoRA: Efficient finetuning of quantized LLMs. In Advances in Neural Information Processing Systems (NeurIPS), volume 36, pages 10088–10115. \#\# Limitations
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