How do I close a rate for all dates past a certain date?

Hi, 

I’m new and in training and setting up my rates. By default it seems anybody can make a booking in the far future. I can put closed restrictions in a certain time window but if I go farther than that in the future then I can book something say in year 3050 no problem. It is kind of weird to me to have such dates open in my system. Are these far-future availabilities pushed to the OTAs and channel managers? Is the only way to protect oneself from such bookings to put a ridiculously high price on the tarif? seems like a hack to me and a malicious user could still make a phony booking... Is there anyway tarifs can be closed for all dates above a certain date ?

Thanks