The <access-date> element has been replaced by the <date-in-citation> element with a @content-type attribute value “access-date” that records the date on which the cited work was examined.

This element is an artifact, now used only within the <nlm-citation> element, which is deprecated. Use of this element is therefore also deprecated.

Some online resources are changing so quickly that a citation to the resource is not complete without the date on which the cited resource was examined, since a day before or a day later, the relevant material might be different. The <date-in-citation> element is now used to record such information inside <mixed-citation> and <element-citation> elements.