What time format is typically expected for compliance evidence in NERC time-bound requirements?

• A. Local time with no seconds.
• B. Moon phase time.
• C. UTC or BES time with precise seconds and a tested clock synchronization process.
• D. Random timestamp.

Answer: (C)

Time-stamped evidence must be anchored to a universal, auditable clock so events can be ordered and verified consistently across systems and audits. The standard practice is to use UTC or BES time with precise seconds, and to rely on a tested clock synchronization process. UTC provides a common reference across all entities, while BES time aligns with the North American bulk electric system context. Including precise seconds ensures exact sequencing of events, which is essential for proving compliance and for after-action reviews. A documented clock synchronization process demonstrates how time sources (like GPS, NTP, or PTP) are used, how clocks are monitored, and how any drift is corrected, so the evidence remains reproducible and trustworthy. Local time without seconds can introduce ambiguity, moon phase time is not a valid standard, and a random timestamp undermines auditability.