This is a fascinating question, and involves the base date encoding of the EAD.


In EAD2002, in <eadheader> one is required to set the @dateencoding, and I believe the only option is “iso8601”. Use of ISO8601 definitely limits what you can put in the @normal attribute.. but I cannot find any documentation that suggests you cannot use alternative values in @era or @calendar…but you get a validation error if you do! This might be a question for the EAD Working Group!


In EAD3, a new option is allowed in @dateencoding within <control> (replacing <eadheader>) for “otherdateencoding”, but you then the alternate code list must be specified in <conventiondeclaration>. Potentially, the alternate code lists that Mike Ferrando suggests (ICU4j) could be used here.



Kelly Revak



American Folklife Center

Library of Congress

101 Independence Ave.

Washington, D.C. 20540-4610

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From: Encoded Archival Standards List <[log in to unmask]> On Behalf Of Mike Ferrando
Sent: Monday, June 22, 2020 9:49 PM
To: [log in to unmask]
Subject: Re: Dates in era/calendar other than ce/gregorian


Calendar (ICU4J 67.1)


Calendar (ICU4J 67.1)




On Monday, June 22, 2020, 9:48:34 PM EDT, Mike Ferrando <[log in to unmask]> wrote:



Dear Palluault Florent,

I think we should use the terms found here (link below).

The attributes in the unitdate element directly correspond to variables (members) for the ICU4j java classes.

In any case, I hope this makes sense.


Mike Ferrando

IT Specialist

Library of Congress




On Monday, June 22, 2020, 3:02:28 PM EDT, PALLUAULT Florent <[log in to unmask]> wrote:



Dear colleagues,


The website dedicated to EAD best practice in French libraries was moved to a different platform about a year ago. You can now find it at The original normative process dates back to 2008-2012 and work started some months ago on an update. French libraries use EAD 2002 and there are currently no plans to move to EAD3.


While working on the <date> element we wondered whether someone could provide a full example of use in an era and calendar other than Common era / Gregorian calendar. There aren't any records of such use in our dataset but we would like to illustrate the possibility, in case some collaborative projects require both the Gregorian calendar and another calendar.


Would the following be correct for a manuscript in Arabic, dating from 1656, with the scribe mentioning in the colophon that he finished his work on 27 Shaʿbān 1066?


    <unittitle>Histoire de la conquête de l'Égypte, copie achevée le <date era="ie" calendar="hijri" normal="10660829" type="autre calendrier">27 Sa'ban 1066 de l'hégire</date></unittitle>

    <unitdate era="ce" calendar="gregorian" normal="1656">1656</unitdate>.


In this example, I made 2 assumptions:

·         Islamic era abbreviated as “ie”

·         Islamic calendar indicated as “hijri”.

Is there a list of terms for eras and calendars and their use in the context of EAD?


Thanks in advance.



Florent Palluault

EAD in libraries working group (France)


Head of special collections
Poitiers public library
Médiathèque François-Mitterrand - 4 rue de l'Université - 86022 POITIERS - FRANCE
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