Date

Definition

Dates associated with events in the life cycle of the resource.

Where Can the Date Information be Found?

In some cases the date may come from accompanying or supplementary information.

Information Sources	Creation date for this kind of item is the date or range of dates when:
For text
title page copyright page cover or inside cover page	the text was published, printed, or revised
For maps
title in a caption or legend notes around the outside of the map	the map was printed
For music scores
top/bottom of page title page table of contents	the music was finished (handwritten) or printed
For videos
title or credit screen(s) label on disc container cover	the video was recorded or publicly released
For sound files
information on disc/cassette container information	the disc/tape was recorded or publicly released
For computer files
title page/screen satement in a header/footer	the content was finished

How Date Works in the Metadata Form

Parts:

1. Date qualifier – drop-down menu

2. Date – text field

Repeatable?

Yes - to include different kinds of date information, click ‘Add’ to repeat all field parts; each individual date type (creation, submission, harvested, etc.) should not be repeated

Required?

No - also see more information about required fields

How Should the Date be Filled in?

General Date Rules

• If no date can be found, leave the field blank

• For each date, be sure to choose the appropriate date type from the controlled vocabulary

• The Special Dates section provides more information about choosing the most relevant format type

• Always format dates appropriately:

Guideline	Pattern	Examples
Basic Format: A single year, month, or day
Write dates Year-Month-Day, separating the sections with a single hyphen	YYYY-MM-DD	1985-03-27
Include partial dates when only the year or only month and year are known	YYYY YYYY-MM	2006 1865-05

• Unless specifically noted, other date types can be any level of specificity (year, month, day), but patterns and examples will not reflect all possible combinations

Guideline	Pattern	Examples
Date Ranges: Inclusive period from a start through an end date
Follow the same basic format, but separate start and end dates with a slash mark	YYYY-MM-DD/YYYY-MM-DD	1941-12/1945-08
If part of the date range is unknown, one date can be replaced with a double-dot to designate an “open” range	YYYY-MM-DD/.. ../YYYY-MM-DD	1889-05-13/.. ../1914-06
One of a Set: Specific unknown date during a known time period (e.g, sometime between 1900 and 1905) or among several options (e.g., July 1980 or 1981)
Dates are enclosed in [square brackets] Separate dates with commas for a list of possible dates or a double-dot for a range	[YYYY,YYYY,YYYY] [YYYY-MM,YYYY-MM] [YYYY..YYYY]	[1909,1919,1929] [1980-07,1981-07] [1939..1945]
Two periods in the set represents specific point within all of the years before/after two dates:
Between 1897 and 1901	[YYYY..YYYY]	[1897..1901]
Before or during 1897	[..YYYY]	[..1897]
During or after 1901	[YYYY..]	[1901..]
Please note: since [square brackets] are used for this notation, they cannot be used to represent dates added from a source other than the item (see Comments for more information)
Multiple Dates: Inclusive, separate dates that are not a single range (e.g., 4th of July 1850 and 1851)
Dates are enclosed in {curly brackets} Separate dates with commas for a list or a double-dot for a range (same as one of a set)	{YYYY,YYYY,YYYY} {YYYY-MM,YYYY-MM} {YYYY..YYYY,YYYY}	{1970,1980,1990} {1850-07-04,1851-07-04} {1939..1945, 2001}
Uncertain Dates: Partially-known or approximate dates
For a single, uncertain date, add a question mark at the end	YYYY-MM-DD?	1958-09?
If a date is approximate (e.g., “circa” dates), add a tilde at the end	YYYY-MM-DD~	1879-03-29~
Any unknown digit can be replaced with “X” A decade can be represented as YYYX Dates with unknown digits cannot also be approximate	YYYX YYYY-MX-DD	189X 1924-1X-17
Seasons: For seasonal dates (such as quarterly publications)
In place of a month, use the season code: 21 – Spring 22 – Summer 23 – Autumn 24 – Winter	YYYY-SS	1926-21 1991-23
Dates with Timestamps: Dates with time precision (requires a specific day)
Separate the date and time with “T”	YYYY-MM-DDThh:mm:ss	2008-05-02T15:07:51
B. C. Dates: Prehistoric dates (will be year only)
Add a hyphen at the front of the date Years must have at least 4 digits	-YYYY -YYYYY	-0601 -50000

*For more information about implementation of the date standard, see the Comments below.

Complex Dates

If you have dates that are approximate, uncertain, or complicated in other ways, it can be difficult to choose the most appropriate formatting. This chart is framed for “creation” dates, but applies to any kind of date, to help explain which format is best to express a date. (For example, coverage dates would be reflect “If the item is about” rather than “If the item was created.”)

If the item was created:	Such as:	Use:	Example:	This means:
During a known time of year	A serial issue from fall 2004 (no listed publication month)	Seasonal date	2004-23	Autumn 2004
During a known decade	A hat from the 1920s	Unknown digit	192X	1920s
At an approximate date	A manuscript written circa 1846	Approximate date	1846~	Approximately 1846
At a specific but uncertain date	A photograph believed to have been taken in 1963 based on context	Uncertain date	1963?	Possibly 1963?
During an approximate uncertain date	A map believed to have been drawn circa 1910	Uncertain/ approximate date	1910%	Approximately 1910?
Over a period of time	A scrapbook compiled 1980-1985	Date range (interval)	1980/1985	1980 to 1985
During an approximate decade	A photograph taken circa 1940s	Date range (interval)	1940~/1949~	Approximately 1940 to approximately 1949
During any approximate date range	A letter written circa 1887- 1890	Date range (interval)	1887~/1889~	Approximately 1887 to approximately 1889
At a particular time within a known range	A map drawn sometime between 1900 and 1920	One of a set	[1900..1920]	Between 1900 and 1920
	A photograph taken at an event held September 12-15, 1974	One of a set	[1974-09-12..1974-09-15]	Between September 12, 1974 and September 15, 1974
At a specific time during a number of dates	A photograph in December, either 1954 or 1958	One of a set	[1954-12,1958-12]	December 1954 or December 1958
At multiple known dates or range(s)	A page with two newspaper clippings from 1902 and November 12, 1920	Multiple dates	{1902,1920-11-12}	1902 and November 12, 1920
	A scrapbook compiled during a student’s senior year 1927-1928 with notes from the start of the next fall	Multiple dates	{1927-08..1928-05,1928-09}	August 1927 to May 1928 and September 1928

Determining Creation Dates

• Whenever possible, enter an original resource creation date

• Be sure to select “Creation” as the date type from the drop-down menu

• If the creation date is unknown, leave the field blank

• When the resource being described is a collection, a date range can be used to describe the creation date range of all the resources

Creation date refers to the date of the exact item described in the record, even if it is a derivation:
If the item is a reprint or revision of an original text:	Use the date of the reprint/revisions Include a note about the original text and printing date
If the item is a copy negative:	Use the date that the copy negative was created The date of the original photographs may be used in coverage
A note about postcards and greeting cards:
If there is no letter or message written on the card:	The item is treated as a photograph or piece of artwork Use the date that the photograph or image was made
If the card has a letter or message written on/in it:	The item is treated as a piece of correspondence Use the date that the card was written/postmarked. If it is important, the date of the picture can be included as part of the coverage

Non-Creation Dates

• Use other types of dates only when they are relevant:

  • Date Harvested - Date that a web-resource was captured for archival purposes

  • Submission Date - Date that the item was submitted for approval by an organization, institution, or agency

  • Acceptance Date - Date that the item was approved by an organization, institution, or agency

• Submission and acceptance dates are primarily used for patents, but may be used for other items when appropriate

  • For patents, the acceptance/approval date and creation date are the same. This may not be true for all items.

• In certain cases, items cannot be made publicly available due to publisher requirements, privacy issues, or other strictures. The Embargo Until Date represents the first date that an item will become accessible to the public or a pre-specified user group. It is used in conjuction with an Embargo note. See also Rights Access

Other Examples

[Letter from Zavala to Santa Anna, March 7, 1829]

Original Resource Creation Date: 1829-03-07

Painting: A Scene from “The Beggar’s Opera”

Original Resource Creation Date: [1728..1729]

Digital photograph: [Bull riding at the Cowtown Coliseum]

Original Resource Creation Date: 2003-12-27T09:16:40

Court case: Documents pertaining to B. C. Wallace as the receiver of the estate and guardian of Campbell minors, cause no. 532, 1896-1904

Original Resource Creation Date: 1896-11-13/1904-12-08

Farmer’s bulletin: Diseases of sheep and goats.

Original Resource Creation Date: 1943-09

University catalog: Catalog of Hardin-Simmons University, 1989-1990 Undergraduate Bulletin

Original Resource Creation Date: 1989

Photograph: Crazy Theatre With Car

Original Resource Creation Date: 1914~

Postcard: [Hamilton Hotel, Laredo, Texas]

Original Resource Creation Date: 1910-01-23

Archived website: U.S.-Canada Power System Outage Task Force

• Original Resource Creation Date: 2004

• Date Harvested: 2009-07-01

Patent: Improvement in Medical Compounds or Bitters for Treating Chills and Fever.

• Original Resource Creation Date: 1873-05-20

• Submission Date: 1873-04-05

• Acceptance Date: 1873-05-20

Comments

• To express the time period(s), date, or date range associated with the intellectual content of the resource, use the Coverage element.

  • For example, a book published in 1976 that is about Texas history from first statehood to 1964 would have an original resource creation date of 1976, but a coverage date range of 1846 - 1964.

• Recommended best practice for encoding the date value is defined in the ISO-approved extension, available at from the Library of Congress: Extended Date/Time Format <http://www.loc.gov/standards/datetime/edtf.html>

  • As of November 2020, the UNTL edit system validates against the approved standard rather than the draft specifications

  • Currently all levels (0 through 2) are supported by UNT Libraries metadata guidelines

    • As of April 2013, the use of [brackets] to represent dates from a source other than the item is no longer permitted in order to support Level 2 functionality

    • This notation has been common practice in traditional library cataloging (using AACR2)

    • To document the fact that a creation/publication date has been added by a metadata creator, a [Display Note][] can be added with text such as “Publication date is not printed on the {item type}.”

  • Local standards for uncertain dates differ slightly from level-1 EDTF extensions:

    • It is valid for the two right-most digits to be “unknown” (e.g., YYXX) however, it is preferred that the date represent at least a decade-level date in order to be helpful for users.

    • This rule also applies to month and day, but it is preferred to revert to the known date level with the assumption that additional granularity/specificity is unknown, e.g.:

      • Represent a year with an unknown month (YYYY-XX) as a year only: YYYY

      • Represent a year and month with an unknown day (YYYY-MM-XX) as a year and month only: YYYY-MM

    • Additionally, the extension allows for ranges to be “unknown” by leaving one side of the range blank vs. “open” using a “..” in place of one date. Generally, local standards prefer the “open” option to denote an explicit choice vs. accidental “/” punctuation.

Resources

• UNT Date Qualifier Controlled Vocabulary

• Library of Congress Extended Date/Time Format

• UNT Extended Date/Time Format Validation Service