  Time dependent CP-violation phenomena are a powerful tool to precisely
measure fundamental parameters of the Standard Model and search for New
Physics. The Belle II experiment at the SuperKEKB energy-asymmetric $e^+e^-$
collider is a substantial upgrade of the B factory facility at the Japanese KEK
laboratory. The design luminosity of the machine is
$8\times{10}^{35}~cm^{-2}s^{-1}$ and the Belle II experiment aims to record
$50~ab^{-1}$ of data, a factor of 50 more than its predecessor. From February
to July 2018, the machine has completed a commissioning run, achieved a peak
luminosity of $5.5\times10^{33}~cm^{-2}s^{-1}$ , and Belle II has recorded a
data sample of about $0.5~fb^{-1}$ . Main operation of SuperKEKB has started in
March 2019. This early data set is used to establish the performance of the
detector in terms of reconstruction efficiency of final states of interest for
the measurement of time dependent CP violation, such as $J/\psi K_0$ , $\eta'
K_0$, and $\phi K_0$. A first assessment of the B flavor tagging capabilities
of the experiment will be given, along with estimates of the Belle II
sensitivity to the CKM angles $\phi_1/\beta$ and $\phi_2/\alpha$ and to
potential New Physics contributions in penguin amplitudes dominated decays and
in $b\to s\gamma$ transitions. In this paper we will present estimates of the
sensitivity to $\phi_1$ in the golden channels $b\to c\bar{c} s$ and in the
penguin-dominated modes $B_0\to \eta' K_0,\quad\phi K_0,\quad
K_0\pi_0(\gamma)$. A study for the time-dependent analysis of
$B_0\to\pi_0\pi_0$, relevant for the measurement of $\phi_2$, and feasible only
in the clean environment of an $e^+e^-$ collider, will also be given.
