Temporal indeterminacy is an inherent problem which arises when capturing and manipulating temporal data in many application areas. As such, representation and manipulation of timestamps with indeterminacy is a requirement for these applications. We present an extension of Allen's thirteen interval relationships to indeterminate temporal intervals based on a novel representation for indeterminate timestamps. The timestamps can be derived from and translated to interval constraints. We provide a set of simple and useful operators for manipulating both convex and non-convex indeterminate intervals represented by these timestamps.