This paper proposes a unified formal environment for spatiotemporal databases and modeling the change in identity of objects. The real world is represented as a set of snapshots consisting of identifiable objects and relations among objects. A database needs transaction time for the consistent management of temporal links among identifiers. Four basic operations affecting object identity are proposed: create, destroy, suspend, and resume. Their compositions are either applicable on a single object (evolve), or on a group of objects (constructive and weak fusion, fission, aggregate and segregate). These operations build a finite set of identity affecting operations — lifestyles. Executable algebraic specifications, written in the functional programming language Haskell, are provided both for the database model and for lifestyles. The specifications of typical lifestyles can be re-used for various application domains.