Alot of my bottles have expiration dates printed on them, And some of those have actually PASSED their expiration date, and they still taste fine to me (I went a little crazy in the beginning buying ALL sorts of pre-mixed juice). No funky colors or tastes

I still write dates on mine So if by some off chance they actually still have liquid in them a year from now I'll know to watch them.
Like everyone else said, keep them in a cool dark place, and they'll last.