Question : query analyzer vs stored procedure

I have the following code which runs inQA yet when put in a stored procedure fails with bad first parameter in dateadd????
set @pdend = '2009/11/30'
set @Q4End = @pdend
set @Q4Start =DateAdd ("m",-3 ,@q4end + 1 )
set @Q3End = dateadd("d",-1,@Q4Start)
set @Q3Start = dateadd("m",-3,@Q3End+1)
set @Q2End = dateadd("d",-1,@Q3Start)
set @q2Start = dateadd("m",-3,@Q2End+1)
set @Q1End = dateadd("d",-1,@q2start)
set @Q1Start = dateadd("m",-3,@Q1End+1)

Answer : query analyzer vs stored procedure

I repeat: do NOT use "m", but use month, mm or m.  without the quotes.