Admittedly, the ARI protocol documentation lacks a sequence diagram, but just consider that the Remote Adapters only have to respond to actions initiated by the Proxy Adapter.
Once connected, a Remote Metadata Adapter should expect to receive a "Notify User" request message on the request stream as soon as a client requests is issued to Lightstreamer Server; after sending the answer, it will be followed by "Notify New Session" and other session related requests.
A Remote Data Adapter, on the other hand, should expect to receive one or more "Subscribe" request messages on the request stream as soon as a client request has been processed by the Metadata Adapter.

We require a "Java compatible millisecond resolution date-time format" to mean a timestamp value as it would be generated by a java "System.currentTimeMillis()" call.
However, the timestamp is only used for debug-level logging by the Proxy Adapter and can be safely valued as 0.

Dario