Purpose: For indicating this constituent property of a date
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