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?
<AGENT_CONNECTION>
<NAME> myAgent </NAME>
<IP> 10.0.0.1 </IP>
<API_VERSION> 1536 </API_VERSION>
<LAST_MESSAGE_TIME> 1618812562 </LAST_MESSAGE_TIME>
</AGENT_CONNECTION>
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).
Note :
The time format for the LAST MESSAGE TIME VALUE is in Unix time (POSIX time) which can be converted into date format (2).