  The breaking of the $CP$ symmetry in $D^0$ meson decays has been awaited for
a long time. After a set of measurements provided by the LHCb, CDF, and Belle
Collaborations leading in march 2012 to combined results that were consistent
with no $CP$ violation at a CL of $0.006\%$ suggesting $CP$ violation at
$\sim1\%$ level. Such a potentially large value of $CP$ violation in charm
decays has triggered widespread interest from the whole particle physics
community to evaluate the implications of such an interesting unexpected
results. However, a more recent combination of more up-to-date results in March
2013, has slightly changed the situation, showing that data are consistent with
the $CP$ conserving hypothesis at $2.1\%$ CL. I briefly review the method used
by the various Collaborations when extracting the quantity $\Delta A_{CP}$ and
the relative results. Finally I discuss the need for additional measurements,
and present the potential of a time-dependent analysis when looking for $CP$
violation in $D^0$ decays and how this can be used to largely improve the
current sensitivity on the mixing phase $\phi_{MIX}$.
