Sixty-five has long been thought of as the point of entry into "old age". We propose a number of life table criteria for answering the following questions: If 65 was considered appropriate four decades ago, what is the corresponding age today? If 65 was (implicitly) a male-oriented definition four decades ago, as we believe it was, what would have been the appropriate definition for women at that time, and what is it today? We address these questions by applying our criteria to 1951 and 1991 Canadian life tables.