Template:Terminology- partial dates

Terminology: Partial date property. These are further modified by date approx property (circa, after, before).


 * date-y: partial date, year. This value is superseded by full date if known.  A value of zero was not set by the user and occurs if there was no known year.
 * date-n: partial date, month. This value is superseded by full date if known.  A value of zero was not set by the user and occurs if there was no known month.
 * Background: Normally the full date is used, and the date-y and date-m properties are left blank ignored. For many persons, only a year and month or just an approximate year is known.  Due to the limitations of sort, persons with missing full dates are not displayed if the sort is on the full date field.  date-y is guaranteed to always exist and have a value regardless whether the user set it. If date exists, the -y and -m values will be derived from it. If date missing, these values will be set to zero (illegal for year and month, so this will not be confused with values that the contributors have set.)