The INTERVAL displayed on the RMCAP represents the RMF collection interval, where the SrvUTime on the RMMSU display represents the 48 five minute buckets that are created for the four hour rolling average.
The SrvUTime is the addition of the WLM LPDATSERVICEUNCAPPEDTIME and the LPDATSERVICECAPPEDTIME times.
Those SrvUTime 5 minute intervals are determined by WLM and the Interval on RMCAP is what is defined for RMF collection interval, so they are both non SYSVIEW definitions.