I'd be interested to see how your system is set up. I'm not sure what you mean by "queue closures",
The standard way to do this is to use Schedules in Attendant. When it comes to a holiday (say) you would use an Annual Schedule (I would recommend using a System Schedule) and then present the caller with different options which simply don't include the queues that are not available
May I suggest you take a look at the "Configuring Call Flows" class which covers this kind of functionality in detail?
HTH