  We study the effect of gravitational time delay on the power spectra and
bispectra of the cosmic microwave background (CMB) temperature and polarization
anisotropies. The time delay effect modulates the spatial surface at
recombination on which temperature anisotropies are observed, typically by ~1
Mpc. While this is a relatively large shift, its observable effects in the
temperature and polarization fields are suppressed by geometric considerations.
The leading order effect is from its correlation with the closely related
gravitational lensing effect. The change to the temperature-polarization cross
power spectrum is of order 0.1% and is hence comparable to the cosmic variance
for the power in the multipoles around l~1000. While unlikely to be extracted
from the data in its own right, its omission in modeling would produce a
systematic error comparable to this limiting statistical error and, in
principle, is relevant for future high precision experiments. Contributions to
the bispectra result mainly from correlations with the Sachs-Wolfe effect and
may safely be neglected in a low density universe.
