States the run timestamp in utc

All 3 scenarios hold

Report timestamps are always stated in UTC, whatever zone the run happened in, so a spec generated in CI reads the same for every reader. The label drops sub-second precision the reader has no use for; the attribute keeps whole seconds.

expected outcome broken scenario
ScenarioRun instantTimestamp attribute?Footer label?
Afternoon run2026-07-20T14:32:09Z2026-07-20T14:32:09Z20 Jul 2026 14:32 UTC
Sub-second precision2026-07-20T14:32:09.123456Z2026-07-20T14:32:09Z20 Jul 2026 14:32 UTC
Turn of the year2027-01-01T00:00:00Z2027-01-01T00:00:00Z1 Jan 2027 00:00 UTC