We propose a formal definition for the timed asynchronous dis-
tributed system model. We present extensive measurements of actual message
and process scheduling delays and hardware clock drifts. These measurements
confirm that this model adequately describes current distributed systems such
as a network of workstations. We also give an explanation of why practically
needed services, such as consensus or leader election, which are not imple-
mentable in the time-free model, are implementable in the timed asynchronous
system model