Why can't I list bulk and inclusive date with finer granularity than just the year?

Sadly this is a pretty complicated issue. The heart of it is that the ISO 8601 date standard is not implemented in any programming languages or relational database (to my knowledge). Even xml schema does not support all of it. Date ranges specifically are not supported in schema. This is why if you look at the declaration in the ead schema for normalized dates that the date datatype is not used. Since the normalized dates can't be stored or manipulated in anything other that a string field we would have write a bunch of custom programming and datatypes to handle the full range of the ISO standard. This would be a considerable amount of programming and testing to make sure we handled everything correctly. Actually I keep hoping that someone else will do the work in java and publish it as open source. Without that we have decided to only support the granularity of a 4 digit year for the normalized version. This way we can store them as integers and get strict typing without having to write extra code. We can always revisit this in the future but my guess is that it will be hard for it to float to the top of the priority list.