Joseph Doherty
099d4783b0
MXAccess fires OnDataChange with pftItemTimeStamp marshaled as a VT_BSTR string (e.g. "3/26/2026 1:38:22.907 PM"), not a FILETIME or VT_DATE. VariantConverter classified it as a plain string, so ApplySourceTimestamp never set MxEvent.SourceTimestamp — every OnDataChange event and every cached ReadBulk result carried no source timestamp for all gRPC clients. Parse the string and set SourceTimestamp. MXAccess formats it in the worker host's local time (verified empirically: a fast-changing tag's timestamp landed exactly the host UTC offset behind wall-clock UTC), so it is parsed as local and converted to UTC. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>