There are a ton of date routines to do all sorts of things.
Here is a very simplistic example:
select Month(dateadd(mm, -1, '2016-01-15')) Mon,
Year(dateadd(mm, -1, '2016-01-15')) Yr
You can build on this and do all sorts of stuff. Check out datediff, datepart, datename, to name just a few.
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How to Post to get the most: http://www.sqlservercentral.com/articles/Best+Practices/61537/