We understand that the last update time for a RIC is dependent upon the underlying feed (broker).
Our question is do Reuters provide a date/time stamp at the time the message is published out by the Java RFA API, so that our application can determine the time taken to receive the update.
It would be helpful to better understand what latency you would like to measure.
Without this understanding, let me try to discuss some scenarios that may be helpful.
Are you looking for latency through the local TREP distribution system? Then the best approach is to use Perormance Tools, that are part of RFA SDK in PerfTools folder, perf provider and perf consumer, perPorvider will add a timestamp and you will find in your docs folder PerfToolsGuide to discuss the exact setup for measurements.
Are you discussing a custom publisher or Elektron service? Then it will be up to the implementor to enter any timestamps or other markers, API does not introduce any by default.
if you are discussing Elektron service, it is not written with RFA, and the timestamps are sourced from exchanges, whatever timestamps are provided by the exchange, and conveyed to the consumer app.
Refinitiv Fix Spec doc contains the detailed descriptions of fields that are populated by the various exchanges.