Date_histogram facets seem to ignore "size" attribute, and sort the opposite of terms facets

I'm seeing two differences between date_histogram facets and terms facets
(ES 0.19.8) and I was hoping for a sanity check here to make sure it's not
a case of pilot-error.

Issue #1: Date_histogram facets don't respect "size" attribute like terms
facets do.

Issue #2: Date_histogram facets do not default to sorting like terms facets
do, which is to say, by their "count" field, ascending.

Below are two example queries I've used to successfully control the size of
the terms facet, but not the date_histogram facet.

curl -X GET '' -d


curl -X GET '' -d


So, are these two behaviors by design, bugs, something else?