Valid time refers to the period during which a piece of information or a data entry is considered accurate and applicable. This concept is crucial in various fields, such as information systems and data management, where the relevance of data can change over time. For example, a promotional offer may have a valid time that starts and ends on specific dates. In the context of temporal databases, valid time helps track when data was true in the real world, as opposed to when it was recorded. This distinction allows users to understand the historical context of information, ensuring better decision-making based on accurate timelines.