Date and time period

The following data type definitions are taken from "XML Schema schema for XML Schemas: Part 2: Datatypes" 

  <simpleType name="date" base="&dtp;recurringInstant">
 	<annotation>
		<appinfo><has-facet name='period'/></appinfo>
		<appinfo><has-facet name='pattern'/></appinfo>
		<appinfo><has-facet name='enumeration'/></appinfo>
		<appinfo><has-facet name='maxInclusive'/></appinfo>
		<appinfo><has-facet name='maxExclusive'/></appinfo>
		<appinfo><has-facet name='minInclusive'/></appinfo>
		<appinfo><has-facet name='minExclusive'/></appinfo>
	</annotation>
    <period value="000000T2400"/>
  </simpleType>

  <simpleType name="time" base="&dtp;recurringInstant">
 	<annotation>
		<appinfo><has-facet name='period'/></appinfo>
		<appinfo><has-facet name='pattern'/></appinfo>
		<appinfo><has-facet name='enumeration'/></appinfo>
		<appinfo><has-facet name='maxInclusive'/></appinfo>
		<appinfo><has-facet name='maxExclusive'/></appinfo>
		<appinfo><has-facet name='minInclusive'/></appinfo>
		<appinfo><has-facet name='minExclusive'/></appinfo>
	</annotation>
    <period value="000000T2400"/>
  </simpleType>

How come the 'date' and the 'time' types have the same period? The "000000T2400" value is period for time. It is 'unit' for date, though. For date (CCYY-MM-DD, see 3.3.22.1) period is "010000". Am I missing something?

The notions of 'period' and 'unit' might be beneficial for simplification of numeric type definition. All types 3.2.2 - 3.2.5 and 3.3.9 - 3.3.21 could be defined (derived from decimal) by assigning corresponding 'period', 'unit' and 'signed/unsigned' constraints. 


Thanks,
 Aram.

Received on Thursday, 30 March 2000 16:28:13 UTC