I'd say we should just change the underlying types to usize rather than have the cast.

Makes much more sense. Still getting to know the crate so might be better suited to somebody more comfortable with the code.

@william20111 Thanks!

@mehcode It is my understanding that usize should be reserved for data that is dependent on the architecture (i.e. pointers/indexes). Some guidelines are discussed here. All of the values being represented in this crate have a very limited domain: 0-59 seconds/minutes, 0-23 hours, 0-31 days of the month, etc. I could safely represent them each as a single u8. In fact, I probably should since I'm storing several trees with dozens of values each and that would be a nice space savings.

I'm going to merge this PR. Please open an issue if you'd like to discuss it further.

@zslayton Makes sense.