Time Control Configuration:
To configure Link Failover you need to use Policy Manager
Select the firewall policy you wish to modify and click on advanced.
Then select the plus icon
Click on the notepad icon with the plus symbol.
This will open up a new window where you can select the hours the policy will be operational.
If you are planning to use this with an Application Policy to block applications during a certain time of day then you must have another policy whereby it allows the subnet or users to pass traffic.