Typically, the year of publication for a book or other work, but also the year “historical” events in a publishing cycle occurred, for example, the year a manuscript was last updated.


The <year> element is used in two contexts: as a part of the metadata concerning book or book component (such as a chapter), and as part of a description of a cited work inside a bibliographic reference (<citation> or <nlm-citation>) element.

Conversion Note: When possible, the year should be expressed as a 4-digit number, for example, “1776”, “1924”, or “0042”.


content-type Type of Content

Model Information

Content Model

<!ELEMENT  year         (#PCDATA)                                    >


Text, numbers, or special characters

This element may be contained in:

<citation> Citation; <date> Date; <nlm-citation> NLM Citation Model; <pub-date> Publication Date; <related-article> Related Article Information; <related-object> Related Object Information; <string-date> Date as a String

Tagged Examples

Example 1

In a bibliographic reference (punctuation and spacing removed):

<ref id="bid.41">
<article-title>A common language for physical mapping 
of the human genome</article-title>
<pub-id pub-id-type="pmid">2781285</pub-id>

Example 2

In a bibliographic reference (punctuation and spacing preserved):

<ref id="B8"><label>8</label>
</name>. <article-title>Effects and costs of 
day-care services for the chronically ill: a randomized 
experiment</article-title>. <source>Medical Care</source>
<year>1980</year>; <volume>18</volume>:
<pub-id pub-id-type="publisher-id">WES-6772889</pub-id>.