Question

Which would be the correct representation of a continuous time signal convolution where
z(t)=x(t)*y(t)
x(t)=u(t-1) with y(t)=u(t-5)
u(T-1)u(t-T-5)
or u(T-1)u(t-T+5)

I don't need the answer it's just something i made up to find out if you are taking the argument of y(t)=u(t-5) making that T then subtracting it from t.