Collective memory is a general category that includes various kinds of memories such as popular, official, autobiographical, cultural, and historical (that produced by scholars). The impact of the passing of time on the collective memory of conflicts, despite its importance, is narrowly addressed in the literature. This article addresses that lack. Empirically, the article is based primarily on a study that examined Israeli collective memory from 1949 to 2004 regarding the causes for the 1948 Palestinian exodus. Methodologically, it is based mostly on content analysis of publications of seven main Israeli–Jewish institutions: the Israeli Defense Forces (IDF), the National Information Center, the Ministry of Education, newspapers, the research community, non-governmental organizations (NGOs) and 1948 war veterans’ memoirs, as well as interviews with key people in these institutions. Theoretically, the article offers various contributions, such as: it proposes that time is a meta-factor which includes fifteen factors influencing collective memory and describes which kind of memory is influenced by each factor and in what way (with focus on the historical memory). The article also discusses the intra-generational process that occurs within the direct-experience generation, differentiates between different modes of influence of the factors (for example, direct and indirect), and proposes that time is an apolitical meta-factor.