The purpose of this invention is to control the influence resulting from body temperature fluctuation on the accuracy of either prediction of ovulation date or menstruation date even when the body temperature has fluctuated before and after the time when actual low temperature is migrating to high temperature. The information processing apparatus determines a short-term days for short-term and a long-term days for long-term based on a plurality of body temperatures measured in periods of historic menstruation, and the determination is done by having the moving average of the short-term become the moving average of the long-term which makes an even lower time, thereby overlapping the menstruation date. The information processing apparatus is used for specifying a moving average of short-term days, based on the measured moving average body temperature of the person under measured in her menstruation, and turns the short-term days moving average into a long-term days moving average so as to produce a higher time sequence. The information processing apparatus predicts the next menstruation date or ovulation date based on the specified time sequence.本發明之目的，係在於就算是當在實際從低溫期而遷移至高溫期之時序的前後而體溫產生上下變動的情況時，亦能夠進行對於精確度之降低作了抑制的排卵日之推測以及生理日之預測的至少其中一者。資訊處理裝置，係針對在過去之月經週期之期間中所測定的複數天數之體溫，而以使短期之移動平均會成為較長期之移動平均而更低的時序，會與生理日相重疊的方式，來決定短期之短期天數和長期之長期天數。資訊處理裝置，係針對在對象之月經週期中所測定的體溫之移動平均，而特定出短期天數之移動平均會成為較長期天數之移動平均而更高的時序。資訊處理裝置，係基於所特定出之時序，來預測下一個生理日，或者是推測出排卵日的到來。
