NIST SP 800-53 Rev. 5 AU-8 — Time Stamps

What this control requires

Uses internal system clocks to generate time stamps for audit records, meeting organization-defined granularity and using Coordinated Universal Time (UTC) or local time with offset. This control supports the System Clock capability within the Audit and Accountability family.

In plain English

Uses internal system clocks to generate time stamps for audit records, meeting organization-defined granularity and using Coordinated Universal Time (UTC) or local time with offset. In practice, this means you can prove you policy management-level controls on a defined cadence.

Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within Audit and Accountability, the assessor will trace your implementation back to the catalogue reference (Control AU-8) and look for objective evidence on the latest two assessment cycles.

How to implement

Logging Monitoring

AWS. Org-trail CloudTrail to a central log archive account, GuardDuty in every region, and Security Hub for cross-source correlation.

Azure. Pipe every diagnostic setting into a central Log Analytics workspace; onboard Microsoft Sentinel for SIEM/SOAR.

GCP. Aggregate audit logs in a dedicated logging project with sink to BigQuery; enable Security Command Center Premium and route findings to Chronicle SIEM.

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

• Policy. Document the trigger, the owner and the cadence.
• Audit. Document the trigger, the owner and the cadence.
• Internal. Document the trigger, the owner and the cadence.
• Time. Document the trigger, the owner and the cadence.
• System. Document the trigger, the owner and the cadence.
• Scope: management, organization, system, records, audit records, time, stamps, capability.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Time Stamps.

Common pitfalls

• Per-account logging that nobody stitches together at the org level — incidents that cross accounts go undetected for days.
• Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• NIST SP 800-171 Rev. 3 3.3.7 — Time Stamps
• HIPAA (45 CFR Part 164) 164.512(h) — Uses and disclosures for cadaveric organ, eye or tissue donation

Related controls in NIST SP 800-53 Rev. 5

• Control AU-12(1) — System-Wide And Time-Correlated Audit Trail
• Control AU-11 — Audit Record Retention
• Control AU-12(2) — Standardized Formats
• Control AU-6(4) — Central Review And Analysis
• Control AU-5(5) — Alternate Audit Logging Capability
• Control AU-12 — Audit Record Generation

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control AU-8

Topics: governance risklogging monitoringpolicy management