Fortunately the Met's data is public, both via API and a 330MB CSV. https://github.com/metmuseum/openaccess https://github.com/metmuseum/openaccess Essentially

Fortunately the Met's data is public, both via API and a 330MB CSV. https://github.com/metmuseum/openaccess https://github.com/metmuseum/openaccess Essentially they have an "Object Date" field that's a human-readable string and could be anything, and then they include "Object Start Date" and "Object End Date" that are integer years so that it's machine readable and you can do those comparisons.