What you are asking can be done with facet queries instead of facet range. Try something like this:
facet.query=myDateField:[NOW-11MONTH/MONTH TO NOW-10MONTH/MONTH]
facet.query=myDateField:[NOW-10MONTH/MONTH TO NOW-9MONTH/MONTH]
facet.query=myDateField:[NOW-9MONTH/MONTH TO NOW-8MONTH/MONTH] ...
and so on.
Now you have ful control over any single facet, so you can do -1DAY in the last facet if you need to. Have a look at the reference for date math syntax: http://lucene.apache.org/solr/4_4_0/solr-core/org/apache/solr/util/DateMathParser.html