Date field

EPrints 3 Reference: Directory Structure - Metadata Fields - Repository Configuration - XML Config Files - XML Export Format - EPrints data structure - Core API - Data Objects

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Metadata Fields: Arclanguage - Base64 - Bigint - Boolean - Compound - Counter - Dataobjref - Date - Decimal - Email - Fields - Float - Id - Idci - Image - Int - Itemref - Keywords - Langid - Longtext - Longtext_counter - Multilang - Multipart - Name - Namedset - Pagerange - Recaptcha - Recaptcha3 - Relation - Search - Secret - Set - Storable - Subject - Subobject - Text - Time - Timestamp - Url - Uuid

Description

This field is used to store a single date. Internally EPrints always uses ISO standard notation for dates, it avoids confusion. This is YYYY-MM-DD.

In bibliographies sometimes exact dates of publication (or other events) are not known. EPrints allows you to store month and year values in date fields. YYYY or YYYY-MM.

In the database EPrints actually uses 3 integer fields to store the date, rather than a built in date field. This is because of the need to allow NULL in month and day if the date is just 1998.

Inheritance

• Metadata
  • Date field

Properties

name	default	description
min_resolution	day	month|year. If set to day then values of YYYY or YYYY-MM will cause a validation error. If set to month then values of YYYY will cause a validation error. If set to year then day, month or year resolutions are allowed.
render_res	day	month|year. If set to year then the dates 1998-10-01, 1998-10 and 1998 would all be rendered as 1998. This is not too useful in configuring the field, but can be set as a print option inside citation files.
render_style	long	long|dow. If long then you'll see 8 September 1998. If short then 08 Sep 1998. dow would render Tuesday 8 September 1998.

Required Phrases

No additional phrases beyond the standard metadata field phrases.

Database

Date fields are stored in the database as:

fieldname_year SMALLINT, fieldname_month SMALLINT, fieldname_day SMALLINT

If a date only has a year value then it would be stored as 1998,NULL,NULL

API

See API page.

Date values are represented in the API as scalars containing ISO encoded dates. eg.

"1976"
"1976-02"
"1976-02-02"

Searching

Date fields can be searched as either single values or ranges. Searching for 2006> will also match 2006-12-25. You can search for 2000- to search dates in or after 2000. Or 2000-12-2003-01 for December 2000 through January 2003.

Examples

Most basic example.

{
    name => 'acceptance_date',
    type => 'date',
}

Set minimum resolution to which the date must be specified is at least a month.

{
    name => 'moratorium_date',
    type => 'date',
    min_resolution => 'month',
}

Set resolution to render to the month, set rendering style to short (e.g. Feb 2023).

{
   name => 'publication_date', 
   type => 'date', 
   render_res => 'month', 
   render_style => short',
}