You have now implemented a module with multiple functions, several of them serving as helpers to a main function. In this case, you were helped by the fact that we planned all these functions for you ahead of time. In the real world you might simply be given the specification for str$\_$to$\_$seconds and be told to come up with the helpers on your own. In fact, seeing as their functions were so short, you might have decided to put all of the code in str$\_$to$\_$seconds, and not bother with helpers at all. This raises an interesting question. Why are helpers useful even when only called once?