Time resolution is set by the VLBI correlator accumulation time. At the VLBA correlator it is about 2 seconds for most programs, although a minimum accumulation time of 131 milliseconds is available. The combination of time and spectral resolution for an observation must result in a correlator output rate of less than 1.0 Megabyte per second (MB/s). Approximate output rates are predicted by the SCHED software (Walker 2006), or see Section 13 for a rough parameterization. Pulsar gating also is available on the VLBA correlator (Benson 1998). The limits on time resolution will become far more flexible when the DiFX correlator becomes operational in 2009.