In this paper, we establish some new oscillation criteria for a second-order delay dynamic equation $$u^{{Delta}{Delta}}(t)+p(t)u( au(t))=0$$ on a time scale $mathbb{T}$. The results can be applied on differential equations when $mathbb{T}=mathbb{R}$, delay difference equations when $mathbb{T}=mathbb{N}$ and for delay $q$-difference equations when $mathbb{T}=q^{mathbb{N}}$ for q > 1.