  Large gauge symmetries in Minkowski spacetime are often studied in two
distinct regimes: either at asymptotic (past or future) times or at spatial
infinity. By working in harmonic gauge, we provide a unified description of
large gauge symmetries (and their associated charges) that applies to both
regimes. At spatial infinity the charges are conserved and interpolate between
those defined at the asymptotic past and future. This explains the equality of
asymptotic past and future charges, as recently proposed in connection with
Weinberg's soft photon theorem.
