Template talk:Terminology- partial dates

The rationale for partial date-y and date-m always existing is that otherwise persons are excluded from reports that use a partial date. There are two cases:
 * Persons where full date is known.
 * Otherwise, A query that used full date would include only persons with full date known. A report using partial date would otherwise only retrieve persons with partial dates.
 * Persons with unknown death dates
 * For example a report that displayed all persons with a particular surname and an unknown birth or death year. For these cases, a person would query for date-y=0.

Future improvements to SMW date handling in queries may one day make some of these conventions obsolete in the future. 16:32, 15 July 2009 (UTC)