Extended Date Time Format
Official Web Site  


Listed below are implementations of EDTF. Please send information about implementations to [email protected].

The Library of Congress provides this list of EDTF implementations as a service to implementers, but does not endorse any of these products nor vouch for the accuracy of the descriptions.

Hefaistos68 / MoreDateTime

Provided by: Andreas Saurwein

An extension library to simplify dealing with .NET's DateTime, DateOnly, TimeOnly and TimeSpan objects, also includes support for the ISO 8601 EDTF profile.

GitHub Link

Updated: May 10, 2023

An EDTF implementation in PHP

Provided by: Jeroen De Dauw

An open-source EDTF implementation in PHP for the Luxembourg Ministry of Culture.

EDTF PHP Library Link

Updated: January 26, 2021

A library for parsing dates using EDTF

Author: Marcell Alexy

Repository         Published Dart package

Updated: November 18, 2019


Provided by: Cory Lown, Duke University Libraries

Used in production by Duke University Library's digital repository to transform dates stored as EDTF strings into human readable strings for display.

Hosted gem: https://rubygems.org/gems/edtf-humanize/

Updated: June 15, 2018


Provided by:Greg Turner <[email protected]>

An implementation of EDTF format in Python, together with utility functions for parsing natural language date texts, and converting EDTF dates to related Python date objects.
see also https://pypi.python.org/pypi/edtf

Repository at https://github.com/ixc/python-edtf

Overview blog post http://info.interaction.net.au/blog/museum-dates-edtf

Updated: July 10, 2017


Provided by: Sylvester Keil <[email protected]>

An implementation of EDTF, based on the working draft of ISO 8601-2. Provides both a parser and a toolkit/date library.

NPM: https://www.npmjs.com/package/edtf
Github: https://github.com/inukshuk/edtf.js
License: AGPL-3.0

Date Listed: June 15, 2016

edtfy javascript date parser

Provided by: Nicolas Barbotte <[email protected]>

A small javascript tool that parses dates and transforms them into edtf. For example, the input "between 2003 and 2004" gives the edtf output "2003/2004".
demo page: http://edtfy.barbotte.net
source code: https://github.com/nicompte/edtfy

Date Listed: December 22, 2015

.NET implementation of EDTF

Provided by: Nathan Harrenstein <[email protected]>


Date Listed: March 25, 2015


A Ruby implementation of the Extended Date/Time Format (EDTF)

Provided by:Sylvester Keil

Gem: http://rubygems.org/gems/edtf
Documentation: http://rubydoc.info/gems/edtf/1.0.0/frames
Source: https://github.com/inukshuk/edtf-ruby

Date Listed: October 31, 2012

Extended Date Time Format Levels 0, 1 and 2 Validation Service

Provided by: Mark Phillips, UNT Libraries


Date Listed: December 19, 2012


Provided by: Richard Tallent, [email protected]

A C# implementation of EDTF for Microsoft.NET and Mono.

Source: https://github.com/richardtallent/EdtfDotNet
License:   MIT

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