A static page creates the illusion that its current text has always been true. In reality, office hours change, professionals move, standards are revised, services evolve, and new evidence can change the appropriate explanation.
Article structured-data guidance recognizes publication and modification dates, while W3C provenance explicitly models revisions. These concepts support a practical maintenance discipline: preserve when material originated, record when it changed, and make substantive revisions traceable.
A revision history does not need to expose every spelling correction. It becomes important when the meaning changes. A regulatory standard may be updated. A professional may revise a position. A location may close. An article may incorporate new evidence. Those changes affect how the material should be interpreted.
Dates also help internal maintenance. If a credential was verified three years ago, the system can flag it for review. If a service page depends on a source that changed, the affected outputs can be identified. If an article has not been reviewed since a major standard changed, that fact is visible.
A living record therefore treats maintenance as part of authority rather than an afterthought. The public record gains credibility by showing that knowledge has a history.