This program implements the contingency periodogram as described in Legendre et al. (1981). The program asks for a time-series of non-metric data (data consisting of classes or ranks) and will determine whether there are repeating patterns in the data. In the case of rank data, the user can define what ranks should be treated as part of a single group or let the program define the partitions based on the maximum entropy approach described in Legendre et al. (1981). The program outputs a plot of the time-series, a plot of the entropy of each period compared to the 95% significance level, and a vector of potentially significant periodicity.