The paradigm of tense and aspect contrasts in Ruhaya, an eastern Bantu language, shows considerable regularity, indication of an ordered system of contrasts. The examination of what appear to be anomalies in the system of contrasts leads to a refinement in the analysis: to the recognition of a tense system that is organised in two stages, based on a model proposed by Gustave Guillaume. Aspectual contrasts are prioritized at the first stage, tense contrasts at the second. Compound forms, which are typically combinations of Stage 2 + Stage 1 (in that order), are complex representations that are marked for both tense and aspect.