The address for a publisher. This is often blank. BibTeX uses the address field for this, but there seems to be some confusion, since lots of people put the author's address in the author field. Use the AuthorAddress, CorpAuthorAddress, or EditorAddress fields for that. No support is offered for ranges that cross year boundaries.
Months are full English names.
I'm getting more woried about how to handle days. If nothing else, the name of the field is misleading. It's also looking like it might be nice to have a Date field that one can just shove stuff into. A utility function would attempt to break it out into parts. The year something was published, or written for unpublished works.