---
title: "NIST 800-171 3.3.7 (AU.L2-3.3.7): Authoritative Time"
description: "NIST SP 800-171 3.3.7 Authoritative Time: 1 SPRS point, allowed on a CMMC POA&M. The text, what assessors check and the evidence."
url: https://policycortex.com/nist-800-171/audit-and-accountability/3.3.7
sealed: 2026-11-11
amended: 2026-11-11
register: nist-800-171/audit-and-accountability/3.3.7
records: 7
digest: sha3:d6868412b5b2cc7b32e8d5a6c28c95b9cec855db081769156f17e266cbf918cc
---

# NIST 800-171 3.3.7 (AU.L2-3.3.7): Authoritative Time

NIST 800-171 / Audit and Accountability / 3.3.7

"Provide a system capability that compares and synchronizes internal system clocks with an authoritative source to generate time stamps for audit records." ([NIST SP 800-171 Rev. 2, requirement 3.3.7](https://doi.org/10.6028/NIST.SP.800-171r2))

CMMC Level 2 practice AU.L2-3.3.7.

## What 3.3.7 means in practice

Logs from different systems only line up if their clocks agree. Systems compare and synchronize their clocks with an authoritative time source, typically through NTP, and audit records carry those time stamps, usually in UTC.

## SPRS points and the CMMC POA&M

- **CMMC Level 2 practice**: AU.L2-3.3.7
- **SPRS points**: 1 point. When it is not met, the DoD Assessment Methodology subtracts 1 from the score of 110.
- **CMMC POA&M**: Allowed. It is worth 1 point, and 32 CFR 170.21(a)(2)(ii) admits requirements worth 1 point. Conditional status also needs a score of at least 88, and the item must be closed within 180 days.

Sources: [NIST SP 800-171 DoD Assessment Methodology, version 1.2.1 (June 24, 2020), Annex A](https://www.acq.osd.mil/asda/dpc/cp/cyber/docs/safeguarding/NIST-SP-800-171-Assessment-Methodology-Version-1.2.1-6.24.2020.pdf); [32 CFR 170.21, Plan of Action and Milestones requirements](https://www.ecfr.gov/current/title-32/section-170.21).

## What an assessor checks for 3.3.7

NIST SP 800-171A gives 3 determination statements for 3.3.7, each found satisfied or other than satisfied. Determine if:

- 3.3.7[a] internal system clocks are used to generate time stamps for audit records.
- 3.3.7[b] an authoritative source with which to compare and synchronize internal system clocks is specified.
- 3.3.7[c] internal system clocks used to generate time stamps for audit records are compared to and synchronized with the specified authoritative time source.

[NIST SP 800-171A (June 2018), assessment objectives for 3.3.7](https://doi.org/10.6028/NIST.SP.800-171A)

## Evidence that shows 3.3.7 is met

- The designated authoritative time source.
- NTP configuration on domain controllers, servers and network devices.
- A check showing systems stay within the allowed difference from that source.

## How PolicyCortex gathers the evidence

No PolicyCortex collector reads the evidence for 3.3.7. Your team provides the evidence listed above.

## Related pages

- **Calculator**: [SPRS score calculator: mark 3.3.7 and the other 109 requirements and see the score.](https://policycortex.com/sprs-score-calculator#family-AU)
- **Sample package**: [Sample package: an SSP, a POA&M and an evidence chain the product generated from demonstration data.](https://policycortex.com/sample-package)
- **Family**: [All 9 Audit and Accountability requirements (3.3).](https://policycortex.com/nist-800-171/audit-and-accountability)
- **Previous**: [3.3.6: Audit Reduction](https://policycortex.com/nist-800-171/audit-and-accountability/3.3.6)
- **Next**: [3.3.8: Audit Protection](https://policycortex.com/nist-800-171/audit-and-accountability/3.3.8)
- **All requirements**: [All 110 NIST SP 800-171 requirements, by family.](https://policycortex.com/nist-800-171)

Meet the requirement once. Keep the evidence current. [Request Access](https://app.policycortex.com/auth?mode=request-access) · [Book a call](https://policycortex.com/book)

## Register colophon

| Seq | Label | SHA3-256 | Prev |
|---|---|---|---|
| REC 0000 | REQUIREMENT | c34c43e52f35 | 3a71507a1c0e |
| REC 0001 | MEANING | 7d9345bcc612 | c34c43e52f35 |
| REC 0002 | POINTS AND POA&M | b791c4efcbf2 | 7d9345bcc612 |
| REC 0003 | ASSESSMENT OBJECTIVES | d0f646d6a186 | b791c4efcbf2 |
| REC 0004 | EVIDENCE | cb215d077c98 | d0f646d6a186 |
| REC 0005 | COLLECTORS | 5be7578adeeb | cb215d077c98 |
| REC 0006 | RELATED | d6868412b5b2 | 5be7578adeeb |

Head sha3:d6868412b5b2cc7b32e8d5a6c28c95b9cec855db081769156f17e266cbf918cc. Each digest is SHA3-256 over the previous digest, the register key, the record label, and the record copy; a second party can recompute it from this document.