One of the basic underlying interests of Karl Mannheim’s social theory of generations in the late 1920s was his interest in understanding social change1 . Despite this original interest, many who have studied generations have focused on specific cohorts, trying to get to grips with the generational identities of baby boomers, or millennials. This trend is further strengthened by the advertising and consumer industries trying to label consumer groups in terms of generation X, Z or the equivalent, in their search for relevant target groups. In this special issue, we would like to return to the theme of generations and social change, with a specific focus on the role of time and memory in the process of generation formation. The themes of generations, time and memory are indeed interrelated in complex webs of interconnections. Social memory is also often related to media, such as the family album of photographs, where – especially during vacations and summer holidays – intergenerational encounters are documented and preserved for posterity. As such, generational theory deals with social processes of change, processes that can also be said to produce time. In the process of ‘generationing’, memories of past experiences, often tainted with nostalgia, are an important ingredient, where people situated in the same location of the historical process can come together through common experiences and the memories thereof. Such remembrances are often mediated in various ways; they can be formed around ‘media events’ , or be focussed on media technologies or contents from one’s formative years. Social memory, as a collective phenomenon, is also characterized by the encounters between different generational memories, as well as of institutionalized forms of memory work, for example in media features of “baby boomers” or “millennials” in the press or on television, providing with prescriptions for how to behave as a member of a certain generation. These encounters also produce time, where the memories of specific generations (or generation units) are relationally situated to other memories. This special issue brings together a group of researchers from Italy, Sweden, Estonia and Portugal, discussing the temporal aspects of generation theory and of memory formation in order to better understand the temporal categories of experience, and of social existence more generally.