The date of acceptance is the point at which the author is notified that: their output has been reviewed by the journal or conference (normally via peer review), all academically necessary changes have been made in response to that review, the article is ready to be taken through the final steps toward publication (normally copy-editing and typesetting). The date of acceptance for conference proceedings is not necessarily the date at which your contribution to the conference was accepted for presentation, but rather the date at which your fully authored research output was accepted for publication in the conference proceedings. Chapters may not have a formal date of acceptance.