http://sqlblog.com/blogs/peter_larsson/archive/2009/09/19/date-and-time-concurrency.aspxIn the past I mostly have given the advice to break down all date intervals into the smallest part (often minutes) and then group by the minute. -- Prepare sample data DECLARE @Data TABLE ( RecID INT IDENTITY ( 1 , 1 ) PRIMARY KEY CLUSTERED , CreateDateenCommunityServer 2.1 SP2 (Build: 61129.1)