  We check formally that the Hubeny-Rangamani-Takayanagi prescription for
holographic entanglement entropy -- when applied to a static black brane
spacetime and to a wide class of subregions that do not lie on a constant time
slice -- gives rise to volume-law entropy in the limit of large subregion. By
volume-law entropy, we mean that the entanglement entropy scales with the
volume of the projection of the boundary subregion onto a static time slice
with respect to the boundary thermal state (with the same coefficient as in the
volume law on the static time slice). Our result applies to subregions that
have reflection symmetry as well as strips, and we also present field-theoretic
arguments in support of our holographic findings.
