Electronic Cultural Atlas Initiative, University of California, Berkeley.

ECAI Going Places in the Catalog: Time Periods.
    One can search for places by using place names but the name and features of place vary with time, so in a well-formed Gazetteer each entry needs a time coding to indicate when the place had that name and/or character.
    Just as locations are referred to by place names so also spans of time are commonly referred to by period names, such as "Neolithic ruins", "Elizabethan drama", "Napoleonic wars" or "Weimar." But time periods, in turn, have a geographical aspect: "Neolithic" denotes different times in different areas. We are working on designs and best practice recommendations for "Time Period Directories" analogous to gazetteers for place names.

Notes on Library of Congress Subject Headings (LCSH) chronological subdivisions
Report: Application of Geographical Gazetteer Standards to Names Time Periods.

For subsequent work, see Support for the Learner project: Time Periods