Well the agreement that we have (it wasn't agreed, it was forced on us) says that the company always has the right to change the roster regardless of what day it is! They can call us (if they can find us) whenever they like and providing we are legal, the contract states we have no option but to comply. Its bloody awful and we've protested until we're blue in the face but we just get told take it or leave. I can't wait to get another job and tell them where to shove it, but until then this one will have to do.