Looking at how to get active agent connections for Policy Server.
smpolicysrv -publish command line seems to publish also Agent connections.
What is the last message time format?
<NAME> myAgent </NAME>
<IP> 10.0.0.1 </IP>
<API_VERSION> 1536 </API_VERSION>
<LAST_MESSAGE_TIME> 1618812562 </LAST_MESSAGE_TIME>
The "Last Message Time" is the element is the Integer value and it is the time since the last message was received from the Agent to Policy Server (1).
The time format for the LAST MESSAGE TIME VALUE is in Unix time (POSIX time) which can be converted into date format (2).