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Using the copulation times from 78 White married women, representing an aver­age of 72 reporting days per woman over a 12-month period, two expected prominent copulatory rhythms were found and described quantitatively. The daily rhythm is characterized by a major evening peak, which encompasses 58% of the daily copulations, and a minor peak in the morning. The weekly rhythm describes a rather constant copulatory rate during weekdays, with a large increase on weekends. The probability of orgasm was found to be significantly greater in copulations taking place after midday. Because of the long-time speculation that the moon plays some role in the timing of human love-making, the data were examined for such a relationship. None was found.