The circadian clock ofNeurospora crassais based on a negative transcriptional/translational feedback loops. Thefrequency(frq) gene controls the morning-specific rhythmic transcription of a sense RNA encoding FRQ, the negative element of the core circadian feedback loop. In addition, a long noncoding antisense RNA,qrf, is rhythmically transcribed in an evening-specific manner. It has been reported that theqrfrhythm relies on transcriptional interference withfrqtranscription and that complete suppression ofqrftranscription impairs the circadian clock. We show here thatqrftranscription is dispensable for circadian clock function. Rather, the evening-specific transcriptional rhythm ofqrfis mediated by the morning-specific repressor CSP-1. Since CSP-1 expression is induced by light and glucose, this suggests a rhythmic coordination ofqrftranscription with metabolism. However, a possible physiological significance for the circadian clock remains unclear, as suitable assays are not available.