When IP filters from IP security policy files are installed into the stack, they are always active by default. Depending on the business need, this might not always be desirable. For instance, you might want to restrict certain types of IP traffic to a specific time, day, or week. IP security provides this flexibility by allowing you to specify a time condition for an IP filter rule. The IpTimeCondition statement specifies when an IP filter or a manual IPSec tunnel is active. You can prescribe not only what traffic is allowed, but when that traffic is allowed, in a way that is not disruptive and without having to edit the IP security policy files.
For more details about the IpTimeCondition statement, see z/OS Communications Server: IP Configuration Reference.