One would certainly have thought that EDTF would have been dropped entirely in favor of the revised ISO 8601. But for reasons that remain unexplained, this is not the case. (EDTF continues to refuse to recognize two digits as a valid way to express a span of 100 years.)

(For those interested: code to convert old-style EDTF dates into new-style EDTF dates has been added to the authority toolkit, but I can't build a new installer until I can get back into the building.)

Gary L. Strawn

Northwestern University Libraries

Northwestern University

1970 Campus Drive, Evanston IL 60208-2300

e-mail: [log in to unmask]<mailto:[log in to unmask]>

office: 847/467-7240

storage facility: 847/467-4619

authority toolkit documentation:

Forsan et haec olim meminisse iuvabit

From: Program for Cooperative Cataloging <[log in to unmask]> on behalf of Stephen Hearn <[log in to unmask]>
Sent: Wednesday, July 15, 2020 9:42 AM
To: [log in to unmask] <[log in to unmask]>
Subject: [PCCLIST] status of EDTF?

Reading the recently released Best Practices for Recording Chronological Data in Bibliographic Records got me curious about the status of EDTF.

At,a%20wide%20variety%20of%20applications<*:*:text=The*20Extended*20Date*2FTime*20Format,a*20wide*20variety*20of*20applications.__;I34lJSUlJSUlJQ!!Dq0X2DkFhyF93HkjWTBQKhk!H_6g58YLxhSrITBtt2agW-spt-PDLtRwI4lTjWd_rrb2lqgTDrMbReOenrcMVRvj8O79$> dated February 4, 2019, we can read the EDTF draft standard.

But at<;!!Dq0X2DkFhyF93HkjWTBQKhk!H_6g58YLxhSrITBtt2agW-spt-PDLtRwI4lTjWd_rrb2lqgTDrMbReOenrcMVW_5Oslv$> dated October 2019, we're advised that "EDTF functionality has now been integrated into ISO 8601-2019, the latest revision of ISO 8601, published in March 2019." We're further advised that "The draft specification is no longer publicly, readily available, because its availability has caused confusion with the official version. It has been archived and is available for research purposes from the Library of Congress upon request."

The first page above has a link labelled "Background" which now connects to the second page above.

Meanwhile, LC's Descriptive Cataloging Manual, Z1, 046 instructs us to use ETDF for formulating dates.

Is the web access to EDTF now unintended, or is the current Background statement misleading about the status of EDTFas a standard? Has EDTF been superseded by ISO 8601-2019?


Stephen Hearn, Metadata Strategist
Data Management & Access, University Libraries
University of Minnesota
170A Wilson Library (office)
160 Wilson Library (mail)
309 19th Avenue South
Minneapolis, MN 55455
Ph: 612-625-2328
Fx: 612-625-3428
ORCID:  0000-0002-3590-1242