How should timestamps be stored to support auditability and interoperability?

• A. Use robust, UTC-based timestamps with time zone metadata, nanosecond precision if needed, and preserve original source timestamp when possible.
• B. Use local time with no time zone to simplify storage.
• C. Store timestamps only as relative offsets from when data arrives.
• D. Drop timestamps to save space.

Answer: (A)

Consistency and unambiguity in time records are crucial for auditability and interoperability. The best practice is to store timestamps in UTC with explicit time zone metadata, use nanosecond precision if needed, and preserve the original source timestamp whenever possible. UTC avoids ambiguity from time zones and daylight saving changes, while the time zone metadata allows correct local rendering and smooth interoperability across systems. Maintaining the original source timestamp preserves provenance for traceability. Relative offsets or omitting timestamps eliminate absolute temporal references, making audits and cross-system comparisons unreliable.