This DateAndTime value is the timestamp of the last time UCS Manager updated this internal backplane link record. It matters on the internal Ethernet link that carries a blade's traffic from the chassis I/O Module up to a Fabric Interconnect over the backplane because it tells an admin how fresh the state shown for this link actually is, which matters when correlating a link event against other logs. A ts value from several hours before a reported outage on this backplane link would tell an admin this record hasn't been refreshed recently, and the current displayed state may already be stale.