How to group by month from Date field using sql

Question

How can I only group by month (and not by day) from a date field?

This is how my date field appears:

2012-05-01

Here is my current SQL:

select  Closing_Date, Category,  COUNT(Status)TotalCount from  MyTable
where Closing_Date >= '2012-02-01' and Closing_Date <= '2012-12-31'
and Defect_Status1 is not null
group by  Closing_Date, Category