This is a guide to select online resources documenting various disruptions to normal academic year scheduling in Harvard's history. Disruptions to normal academic life and scheduling have included contagions, war, severe weather conditions, and societal crises.

This guide also provides a complete list of the specific dates on which Harvard has held its nearly 400 commencements since 1642 as well as a description of the reasons under which ten commencements in the 17th and 18th centuries were canceled.

Resources for compiling all of this information are listed in the "Additional Resources" section of this guide with the expectation that these sources should be consulted for more details about both commencements and academic year disruptions.

This guide is a work-in-progress and content is subject to change and/or clarification. Please feel free to contact our staff at archives_reference@harvard.edu if you notice questionable or confusing information.