# Point-in-time data

> Point-in-time data records what a source said at each moment, so a model or eval can be restricted to information that existed on a given date.

URL: https://data.arietalabs.com/glossary/point-in-time/

For legal AI this prevents leakage: an eval question about the law on 1 March 2025 should not be answerable from an amendment published in June 2025. The history SKU makes this possible: version N is current from its fetchedAt until version N+1’s.

Arieta Data versions are observation snapshots, not reconstructions of the law in force; history starts when a document first entered the corpus and cannot be backfilled.

Sources:
- [Arieta Data history SKU](https://data.arietalabs.com/datasets/history/)