If they are vacuum sealed then I would say 6 months, if they are just in freezer bags I would say 2 months. But thats just my opinion and I don't use FT anymore.
I think there is a slight difference between the freezer time for rodents that are so young they have no great amount of fur (pinkies & fuzzies) and the older ones. Best advice I can give is to use a good f/t supplier and simply phone them for advice on this. They are afterall the experts on their own product.
I've had some rats for over a year vacume packed with no problems. I think that some of the vitamins break down over time but I have no evidence to prove or disprove that.
~Jake~
Too many boas to list and a few balls as well