sql server - SQL filter result to current month and previous two months -

here sql code:

select  month   = datename(month,dateadd(mm,datediff(mm,0,starttime),0)),  cast ((round(((convert(decimal(10,2),sum(duration)/60)/60)),2)*55) numeric(36,2))  vexecutionglobalhistory tester <> 'dit2988' , testtypeid = 1   group dateadd(mm,datediff(mm,0,starttime),0), year(dateadd(mm,datediff(mm,0,starttime),0))  order dateadd(mm,datediff(mm,0,starttime),0), year(dateadd(mm,datediff(mm,0,starttime),0)) 

this query returns:

april|123   may|3456  june|856  july|345 

i want return following:

  may|3456  june|856  july|345 

does have ideas? im using microsoft sql server management studio 2010

the following return first day of month, 2 months today:

select cast(dateadd(month, datediff(month, 0, getdate())-2, 0)as date) 

so can add where criteria:

select  month   = datename(month,dateadd(mm,datediff(mm,0,starttime),0)),  cast ((round(((convert(decimal(10,2),sum(duration)/60)/60)),2)*55) numeric(36,2))  vexecutionglobalhistory  tester <> 'dit2988' , testtypeid = 1        , starttime >= cast(dateadd(month, datediff(month, 0, getdate())-2, 0) date) group dateadd(mm,datediff(mm,0,starttime),0), year(dateadd(mm,datediff(mm,0,starttime),0))  order dateadd(mm,datediff(mm,0,starttime),0), year(dateadd(mm,datediff(mm,0,starttime),0))