Vivek
Trying to understand the thought process OR value behind collecting Web Agent creation date for PStore cleanup. What we really want is when was the Web Agent last used e.g. Created a Web Agent 5 years ago for an App-1, but that Web Agent is still sending request VS Created a Web Agent 2 years ago for an App-2, which has been decomm'ed hence no request from that Web Agent. Typically what Web Agents are still active could be identified from policy server audit logs (other alternatives is enabling Agent Instances feature OR SNMP OR OneView Monitor OR CA APM for SSO, but I'd personally doing it via audit logs for sake of simplicity/ease).
Nevertheless since the question has been asked for how to collect creation date.
Using XPSExplorer, If we choose to view an object, it does display the creation date.
Note : Creation Date may not reflect the actual creation date, because it may have been re-registered. We can run the same approach for Agent Objects as well.
I'd suggest normally, export all Trusted Host Object to Xcart and then onto a output file and / OR Using REST API (R12.8) and / OR Using SDK e.g. PERL API, although I'm not very confident, if the creation date is exposed via either of these options.