Fixed read/write issue for certain locales.

I've confirmed the fix with users.

In certain locales, or perhaps for people that travel, saving and loading is inconsistent and loads as either nil or 01-01-2001. 

If a locale isn't specified on the save, I believe iOS uses whatever locale is currently set. If that changes, this can cause problems.

The locale needs to be forced on read and write to have data consistency.