Comments by Dennys Henry (Top 1 by date)

Sorry about that. If it's a datetime field, you have to first cast it to a date (which might be a lot of work), it works just fine for me since most of the fields am working on are just date fields and not datetime.

However if you test SELECT SUBSTRING(CAST(CAST(GETDATE() AS DATE)AS NVARCHAR),1,7) you get '2015-09' / '2015-10' etc