ChronoCorpus is an open-source service developed and provided by CLARIN. It consists of carefully selected samples of Polish daily press texts, organized according to the chronological criterion. Currently, the time range covers the years 1940-1962, but it is intended to be extended. Press samples are standardized, ordered by publication time, and annotated with the appropriate metadata. The service allows users to discover and study the dynamics of events and phenomena represented in the daily press over long periods of time. The corpus is strongly oriented to the needs of researchers representing the humanities and social sciences, whose circles include, among others linguists, lexicographers, historians, anthropologists and political scientists.