In relativistic gravity, requiring a spacetime hypersurface be a Killing
horizon breaks the general covariance of general relativity. The residual
algebra of horizon preserving diffeomorphisms can be extended to a Virasoro
algebra near the horizon, the central charge of which yields the
Bekenstein-Hawking entropy via the Cardy formula. This near horizon symmetry
approach provides an argument for why black hole entropy computations in
various quantum gravity models all agree. An exception may be
Ho\v{r}ava-Lifshitz gravity, where causal horizons are not Killing horizons but
rather universal horizons. As a first step towards determining if the entropy
of universal horizons can be calculated by a near horizon symmetry approach we
compute the classical algebra of universal horizon preserving diffeomorphisms.
We find that the algebra is similar to the algebra in the Killing horizon case,
but with a modification that agrees with other approaches to universal horizon
thermodynamics.
