This essay provides a reflection on the space-time profile of migrants in advancedsocieties. Employing the concepts of sympatry, allochronism and socialtime, the conclusion is that migrants and natives are sympatric and allochronicgroups; that is, while they are sharing the same space, they don’t share thesame time. The time lag is theoretically and empirically argued and supportedby statistical data in order to show the migrants’ non-coevalness condition. Inparticular, the concept of allochronism is carefully analysed and purified fromideological connotations to give a heuristically meaningful role. Finally, the resultsare used to examine the Schütz’s concept of social world and the typologyof relations that structured it (predecessors, successors, consociates, contemporaries).In the light of the above considerations, the latter seems inadequate toaccount for the space-time position of migrants and therefore requires a conceptualrevision