  The measurement of the tunneling time-delay in attosecond experiments, termed
attoclock, despite its controversies, offers a fruitful opportunity to
understand the tunneling time and the tunnel-ionization process. In previous
work, we showed a model that well describes the time-delay measured by the
attoclock experiment in the adiabatic and nonadiabatic field calibrations. In
the present work we show that the tunneling time reveals a universal behavior,
with disentangled contribution, where the barrier time-delay can be
convincingly defined and determined from the difference between the time-delay
of adiabatic and nonadiabatic tunnel-ionization, with good agreement with the
experimental result. Furthermore, we show that in the weak measurement limit,
the barrier time-delay corresponds to the Larmor-clock time and the interaction
time within the barrier.
