Sense 2.0.0-beta1 autocomplete missing "month"

The autocomplete doesn't have "month" in the list for doing date_histogram aggregations.
("year", "day" etc are present, but "month" is not).

(kibana version 4.3.1 build 9517, elasticsearch version Version: 2.1.1, Build: 40e2c53/2015-12-15T13:05:55Z, JVM: 1.7.0_95)

The issue names no files or tests. Start by locating the autocomplete data or entry point for date_histogram aggregation intervals, then compare the existing year and day entries with the missing month entry. Done means month appears in the autocomplete list for date_histogram aggregations.

Written by the indexing model from the issue text.