Company dates indicate the points in time when the status of a company changes.

The year of foundation identifies the start of a company's active existence. The year of liquidation identifies the end of its existence as an active functioning entity. These two measures express the respective events as calendar years.

A company status describes a condition, while a company date identifies when a change occurs. A foundation date does not imply that a liquidation has occurred or that a liquidation date is known. Dates of work on a building concern that building's life cycle rather than the company's existence.