Reproducing Omitted Temporal Expressions in Japanese News for Retrieval-Augmented Applications

Tomoaki Yasuda, Shotaro Ishihara


Abstract
News articles often contain omitted temporal expressions, such as day-only or month-only mentions, which must be interpreted with reference to the publication date. When such articles are indexed or processed as standalone text in search and retrieval-augmented generation (RAG) systems, these omissions can cause temporal mismatches and unstable interpretation by large language models. We focus on reproducing omitted temporal expressions as concrete dates or intervals using the publication date as external context before the articles are indexed for search and RAG applications. Specifically, building on established temporal-expression extraction and normalization techniques and informed by a manual analysis of Japanese news articles, we propose jaROTE, a rule-based pipeline for Japanese news. Experiments on two news corpora demonstrate that jaROTE achieves high performance, and remains competitive with LLMs while providing a fast, low-cost pipeline. We further show that temporal reproduction improves time-constrained lexical retrieval, demonstrating the practical value of publication-date-grounded normalization for Japanese news retrieval.
Anthology ID:
2026.emnlp-industry.236
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
3945–3956
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.236/
DOI:
Bibkey:
Cite (ACL):
Tomoaki Yasuda and Shotaro Ishihara. 2026. Reproducing Omitted Temporal Expressions in Japanese News for Retrieval-Augmented Applications. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 3945–3956, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Reproducing Omitted Temporal Expressions in Japanese News for Retrieval-Augmented Applications (Yasuda & Ishihara, EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.236.pdf