  We study theoretical neutrino signals from core-collapse supernova (CCSN)
computed using axisymmetric CCSN simulations that cover the post-bounce phase
up to $\sim 4$~s. We provide basic quantities of the neutrino signals such as
event rates, energy spectra, and cumulative number of events at some
terrestrial neutrino detectors, and then discuss some new features in the late
phase that emerge in our models. Contrary to popular belief, neutrino emissions
in the late phase are not always steady, but rather have temporal fluctuations,
the vigor of which hinges on the CCSN model and neutrino flavor. We find that
such temporal variations are not primarily driven by proto-neutron star (PNS)
convection, but by fallback accretion in exploding models. We assess the
detectability of these temporal variations, and find that IceCube is the most
promising detector with which to resolve them. We also update fitting formulae
first proposed in our previous paper for which the total neutrino energy (TONE)
emitted at the CCSN source is estimated from the cumulative number of events in
each detector. This will be a powerful technique with which to analyze real
observations, particularly for low-statistics data.
