Investigating the evolution of historic architecture or archaeological sites most often starts with the cumbersome task of putting together various pieces of information, each with its specific characteristics in terms of precision, scope and reliability. Naturally, time slots are among the main clues analysts expect to spot when filtering and cross-examining these pieces of information. But due to the very nature of historic data sets - heterogeneity, uncertainty, missing data, uneven distribution in time (etc.) - time points and intervals the analyst will identify are often inconsistent in terms of granularity. In this contribution we propose a generic framework for visualising time with multiple granularities. It is applied on two very different test cases - the analysis of an individual artefact's lifetime, and a comparison of stylistic trends inside / between territories.