A method and apparatus to establish a trustworthy local time based on trusted computing methods are described. The concepts are scaling because they may be graded by the frequency and accuracy with which a reliable external time source is available for correction and/or reset, and how trustworthy this external source is in a commercial scenario. The techniques also take into account that the number of different paths and number of hops between the device and the trusted external time source may vary. A local clock related value which is protected by a TPM securely bound to an external clock. A system of Accuracy Statements (AS) is added to introduce time references to the audit data provided by other maybe cheaper sources than the time source providing the initial time.