<unitdate> Date of a Unit

<unitdate> is used to encode the creation year, month, or day of the described materials. It may in the form of text or numbers and either a simple date or range. It is found within <did> and its subelements and is only used to encode creation or relevant dates of described materials. Other types of dates should be encoded within <date>. It is comparable to ISAD(G) element 3.1.3, and MARC fields 245 subfield f for inclusive dates, 245 subfield g for bulk dates, or 260 subfield c.

<unitdate> may be used within <archref>, <did>, <entry>, <event>, <extref>, <extrefloc>, <item>, <label>, <p>, <ref>, <refloc>, <unittitle>.


  • ALTRENDER – not required. Use if the content of the element should be displayed or printed differently than the rendering established in a style sheet for other occurrences of the element.
  • AUDIENCE – not required. Use to set whether the element’s contents will be visible to external users or to internal ones. Possible values are: “internal” and “external.”
  • ID – not required. Creates an ID for element. Can be used for linking.
  • CALENDAR – not required. Default value is “gregorian.”
  • CERTAINTY – not required. May be used to indicate degree of precision used in dating—”circa,” “approximately,” “after,” etc.
  • DATECHAR – not required. May be used to characterize the nature of the dates, such as “creation” or “modification.”
  • ENCODINGANALOG – not required. May contain information to map this tag to a particular element in another schema.
  • ERA – not required. May be used to indicate the era in which the date falls. Default values is “ce” for “Common” or “Christian” era.
  • LABEL – not required. This can be used when a meaningful display label for an element can’t be derived by the stylesheet from its name. It is available in all <did> subelements.
  • NORMAL – not required. A standard numeric form of the date used for machine reading and comparison, i.e. YYYYMMDD, YYYY/YYYY, etc. Should particularly be used if the text within the element is not written out as YYYMMDD.
  • TYPE – not required. May be used to specify whether the date is “bulk” or “inclusive.”


<unitdate> may contain PCDATA, <abbr>, <archref> <bibref>, <emph>, <extptr>, <extref>, <lb />, <linkgrp>, <ptr>, <ref>, and <title>.


Use DACS Section 2.4, Date. Required. (DACS 2013, pp.24-27)


	<unittitle label="Title">Letters of Sarah J. Bell Kitchin <unitdate normal="1963/1985">1963 to 1985</unitdate></unittitle>
<c level="series">
		<unitdate normal="1963/1985" datechar="creation" type="inclusive">1963 to 1985</unitdate>

EAD tag library entry for <unitdate>.