Semium Time Vocabulary
Semium Time is a vocabulary of time periods: milleniums, centuries, half centuries, quarters, decades, and years. It also includes historical periods, like middle ages. Each term has several multilingual labels, and their URI's are resolveable to human-readable html.
Download as zipped RDF/SKOS, or browse it online.
Semium Time was originally developed to describe time expressions used in Europeana and to show them on a timeline. It can be used for other applications as-is or with custom modifications.