  Associated to the unique 4-parametric subgroup of translations, normal to the
Bondi-Metzner-Sachs group, there exists a generator of the temporal translation
asymptotic symmetry. Such a descriptor of the motion along the conformal orbit
near null infinity is propagated to finite regions. This allows us to observe
the global energy conservation even in extreme situations near the critical
behavior of the massless scalar field collapse in spherical symmetry.
