Terminology: A Date property is not directly set via a parameter. Instead it is formed of constituent parts so that partial dates may be input.

The constituent parts are postpended to the event (eg: birth_year). The properties are:

• year (if the property value is 9999, then the year is unknown)
• month
• day
• hour (Hour and minute: If indicated, please convert to Greenwich / GMT /UTC )
• minute
• if-bce (if true, the add "BC" to date.

• Background: This is a revision of the original date scheme in which constituent parts of dates were derived from full date fields. The following fields are obsolete
  • date-y, date-m.

• Type:number
• subproperty of (allows search on) Event year