Does the Temporal Focus of Information Affect Confidence Calibration in LLMs? A Study of Temporal Effects on Model Confidence

Bhawna Piryani, Jamshid Mozafari, Adam Jatowt


Abstract
Large language models (LLMs) are widely used as factual knowledge sources, yet reliable deployment requires not only accurate predictions but also well-calibrated confidence estimates. While prior work on temporal robustness has primarily focused on changes in factual accuracy over time, we study temporal confidence calibration: whether model confidence remains aligned with correctness across questions associated with different reference times. We evaluate multiple LLMs on temporally grounded question answering benchmarks spanning both historical and dynamically evolving facts, comparing five confidence estimation strategies using Expected Calibration Error (ECE) and Brier Score computed across temporal slices. Our experiments reveal substantial temporal miscalibration: as factual accuracy varies across time, model confidence often fails to track these changes proportionally, leading to pronounced overconfidence on time-sensitive queries. Across the evaluated confidence estimators, no single method consistently dominates: P(True) and Token Probability Confidence perform best most often, while the optimal estimator varies across models and datasets. We further show that global temperature scaling improves calibration but leaves meaningful period-specific variation, indicating that standard post-hoc calibration does not fully eliminate temporal miscalibration. These findings highlight temporal calibration as an important and previously underexplored dimension of LLM reliability.
Anthology ID:
2026.findings-emnlp.1854
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
39582–39610
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1854/
DOI:
Bibkey:
Cite (ACL):
Bhawna Piryani, Jamshid Mozafari, and Adam Jatowt. 2026. Does the Temporal Focus of Information Affect Confidence Calibration in LLMs? A Study of Temporal Effects on Model Confidence. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 39582–39610, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Does the Temporal Focus of Information Affect Confidence Calibration in LLMs? A Study of Temporal Effects on Model Confidence (Piryani et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1854.pdf