  Irreversibility is commonly quantified by entropy production. An external
observer can estimate it through measuring an observable that is antisymmetric
under time-reversal like a current. We introduce a general framework that,
inter alia, allows us to infer a lower bound on entropy production through
measuring the time-resolved statistics of events with any symmetry under
time-reversal, in particular, time-symmetric instantaneous events. We emphasize
Markovianity as a property of certain events rather than of the full system and
introduce an operationally accessible criterion for this weakened Markov
property. Conceptually, the approach is based on snippets as particular
sections of trajectories, for which a generalized detailed balance relation is
discussed.
