How does Jekyll date formatting work?

I'm using Jekyll to generate a simple site.

I want the date field to display in the format 12 September 2011.

I've found, through some creative googling, a bit of date-format manipulation, but nothing that seems to get me the month name. What I have is {{ page.date| date: "%m-%d-%Y" }}, which gets me output as 09-12-2011, but isn't quite what I'm looking for.

Is there any way to get the month as a name in Jekyll?

Or, barring that, is there any documentation for the date attribute?