Non-profit organizations are faced marketing issues : recruiting volunteers and improving their loyalty. To answer them, they target retirees, focusing on their daily free time. However, they forget that their time is a limited resource, because of the proximity of their own finitude. Why volunteering when time is running out ? This research aims to explain the variety of retirees’ motivations to volunteer by what they experience when considering time remaining to live. We shed light on a new temporal concept: ultimate time pressure (UTP), to gain a better understanding of what retirees think about their limited time remaining to live and the feelings related. After a literature review on volunteerism and motivations underlying this behavior, another literature review on time experience with ageing leads us to create a new concept: ultimate time pressure ; and to build a theoretical model. In chapter 3, we progressively enrich it, thanks to a thematic content analysis of 18 interwiews, with Nvivo10 software. The variables, hypothesis and research design follow. Next, a quantitative study (N= 728) leads us to create an UTP scale, to examine psychometric properties of the other scales (chapter 5) and finally to test the hypothesis. The main results described in chapter 6 shows the influence of UTP on motivations to volunteer by retirees, its determinants and consequences. The main academic contribution is the add of a third kind of time pressure and the scale related. This research has also practical and societal issues. It encourages non-profit organizations to consider the heterogeneity of retirees, for a better strategical and mix marketing (typology : 5 segments of retired volunteers).
