Pitfalls in transaction time

Impreciseness of the notion of “transaction time” is clarified. Uncertainty in application of “transaction time” as “the starting time of the existence of a database record” or “when we got to know” is pointed out. Questions of computer clock synchronization and currently available methods for computer clock synchronization are resumed. Examples of faults in temporal data interpreted as transaction time data in applications are introduced. Safe approaches to the design of systems with temporal data are proposed.