all the dayname dates of a previous month

DECLARE @dt DATE = getdate()

select dateadd(week,-n, dt) dt from (Select @dt dt) src 
cross apply (values(1),(2),(3),(4),(5),(6),(7),(8),(9)) d(n)
WHERE dateadd(week,-n, dt)>EOMONTH(@dt,-2) 
and  dateadd(week,-n, dt)<= EOMONTH(@dt,-1)