This DateAndTime field records the timestamp at which this specific archived FCoE interface sample was originally captured, before it rolled off the live object into history. Because FCoE interface history keeps a rolling set of past samples, this per-record timestamp is what lets an admin line up an archived snapshot with an event in another log (an alarm, a reboot, a config change) at the exact moment it happened. For example, matching this timestamp against a syslog entry for a link flap on the same interface would confirm whether that particular archived stats record was captured during the outage.