  A statistical model for describing the scaling of the distribution of
inter-event times is described. By considering the diverse region seismicity
(natural and induced) at different scale levels the self-similarity of the
distribution has been determined. Significant deviations occur only in the area
of maximum magnitude (maximum energy class). A comparison between the
distribution of inter-event times at different scale levels and the most
popular distributions of reliability theory has been carried out. The
distribution of inter-event times for different scale levels is well
approximated by the Weibull distribution. The Weibull distribution, with
parameters which obey the scaling model and the Gutenberg-Richter law, have
been tested.
