Temporal facts

A temporal fact is a value stored with the period it was true for and the history of when it was seen, rather than as a single current value that overwrites its predecessor. It is needed because companies change: names change, registered offices move, directors come and go, status moves from active to liquidation. A store that keeps only the current value can answer 'what is the address' and cannot answer 'what was the address when we onboarded them', which is the question that matters in a dispute, an audit or a KYB refresh.

Doing this properly needs two independent time axes. Valid time is when the fact was true in the world; transaction time is when the system learned it. They are different, they move independently, and a system with only one of them will eventually assert that a fact became true on the day it was loaded. Half-open intervals are the conventional representation, so that consecutive periods abut without overlapping.

Temporal facts also change what a confidence score can mean. A value seen once six months ago and a value confirmed by three sources this month are different evidence, and a model that stores only the value cannot distinguish them.

Entity Bind stores facts with the source's own effective date where the source publishes one, a first-seen timestamp, a last-checked timestamp and a confirmation count. Survivorship ranks on last confirmed rather than on first seen, and re-confirmations by the same source are counted separately from independent corroboration, so the two counts stay distinguishable.