select

DT,

WeekOfQuarter=(datediff(dd,dateadd(QQ,datediff(QQ,0,DT),0),DT)/7)+1

from

( -- Test Data

select DT = convert(datetime,'20090403') union all

select DT = convert(datetime,'20090625')

) a

Results:

DT WeekOfQuarter

------------------------------------------------------ -------------

2009-04-03 00:00:00.000 1

2009-06-25 00:00:00.000 13

(2 row(s) affected)