Reports, as text, when the currently active policy was installed on this gateway. Comparing this timestamp across a cluster after a policy push is how an admin confirms the install actually completed at roughly the same time everywhere, rather than trusting the management console's success message alone; a gateway with a stale fwInstallTime despite a reported successful push indicates the install didn't actually take. Example: one cluster member showing an fwInstallTime three hours older than its peers, despite the management server reporting a successful fleet-wide push, flags that specific gateway for a manual reinstall.