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".
|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. If "long" then you'll see "8 September 1998". If "short" then "08 Sep 1998".|
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
Date values are represented in the API as scalars containing ISO encoded dates. eg.
"1976" "1976-02" "1976-02-02"
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.