AU-8: Time Stamps

CSF v1.1 References:


  • Low
    • AU-8
  • Moderate
  • High

Next Version:

Control Statement

The information system:

  1. Uses internal system clocks to generate time stamps for audit records; and
  2. Records time stamps for audit records that can be mapped to Coordinated Universal Time (UTC) or Greenwich Mean Time (GMT) and meets [Assignment: organization-defined granularity of time measurement].

Supplemental Guidance

Time stamps generated by the information system include date and time. Time is commonly expressed in Coordinated Universal Time (UTC), a modern continuation of Greenwich Mean Time (GMT), or local time with an offset from UTC. Granularity of time measurements refers to the degree of synchronization between information system clocks and reference clocks, for example, clocks synchronizing within hundreds of milliseconds or within tens of milliseconds. Organizations may define different time granularities for different system components. Time service can also be critical to other security capabilities such as access control and identification and authentication, depending on the nature of the mechanisms used to support those capabilities.

Control Enhancements

AU-8(1): Synchronization With Authoritative Time Source


  • Moderate
  • High

The information system: Compares the internal information system clocks [Assignment: organization-defined frequency] with [Assignment: organization-defined authoritative time source]; and Synchronizes the internal system clocks to the authoritative time source when the time difference is greater than [Assignment: organization-defined time period].

AU-8(2): Secondary Authoritative Time Source


(Not part of any baseline)

The information system identifies a secondary authoritative time source that is located in a different geographic region than the primary authoritative time source.