On a "dies religiosus", individuals were not to undertake any new activity, nor do anything other than tend to the most basic necessities. On the calendar under the Republic, a "dies natalis" was an anniversary such as a temple founding or rededication, sometimes thought of as the "birthday" of a deity. During the Imperial period, some of the traditional festivals localized at Rome became less important, and the birthdays and anniversaries of the emperor and his family gained prominence as Roman holidays. On the calendar of military religious observances known as the "Feriale Duranum", sacrifices pertaining to Imperial cult outnumber the older festivals.