For your main inquiry, yes this is indeed configurable.
If you have the rule already configured and you still don't get your desired result, you might need to check the rule tracing to find the reason.
I have created a working sample rule which blocks the access to any search engines for the months of July to December.
You may try to change the value of the month to make sure your rule works. Adjust it to 8 and your access to google should be allowed by MWG.
Make a test rule first to familiarize yourself on the rule maneuvering.
Ohhhhooo!!! Attempt this rule.I hope it will do with stop cycle.
Have u added url filter anywhere? because,I can not see it in your rule set.Moreover,if you want to allow facebook for a month.Please add a rule as i specified with stop cycle.It is working fine in my environment.
No No in my case i have configured bit different way, this is inside URL blocking rule.
I have enabled for youtube.com.
I am really sorry...Now I am unable to capture, what you really want to allow.