  We consider a family of second-order parabolic operators
$\partial_t+\mathcal{L}_\varepsilon$ in divergence form with rapidly
oscillating, time-dependent and almost-periodic coefficients. We establish
uniform interior and boundary H\"older and Lipschitz estimates as well as
convergence rate. The estimates of fundamental solution and Green's function
are also established. In contrast to periodic case, the main difficulty is that
the corrector equation $
(\partial_s+\mathcal{L}_1)(\chi^\beta_{j})=-\mathcal{L}_1(P^\beta_j) $ in
$\mathbb{R}^{d+1}$ may not be solvable in the almost periodic setting for
linear functions $P(y)$ and $\partial_t \chi_S$ may not in
$B^2(\mathbb{R}^{d+1})$. Our results are new even in the case of
time-independent coefficients.
