First things first. We need some consumable ddl and sample data. I created this for you this time so you can see what I mean.

if OBJECT_ID('tempdb..#Something') is not null

drop table #Something

set dateformat mdy

create table #Something

(

dt1 datetime,

dt2 datetime,

dt3 datetime,

dt4 datetime,

dt5 datetime

)

insert #Something

select '3/31/2011', '3/30/2011', '4/4/2011', '3/30/2011', '4/4/2011' union all

select '10/24/2012', '10/23/2012', '10/27/2012', '10/23/2012', '10/27/2012' union all

select '12/10/2012', '12/8/2012', '12/19/2012', '12/8/2012', '12/19/2012' union all

select '12/20/2012', '12/8/2012', '12/19/2012', '12/8/2012', '12/19/2012' union all

select '1/16/2013', '1/14/2013', '1/24/2013', '1/14/2013', '1/24/2013'

select * from #Something

So based on your sample data what do you want for desired output? I would like to point out that you do not have any duplicate rows here at all. Can you explain what you mean by that?