<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified" version="0.6.50">
	<xsd:annotation>
		<xsd:documentation>
		**********************************************************************  Overview  **************************************************************
				This is an ADN item-level CATEGORY schema.
				Tags defined: temporalCoverages
		
				Time interpretation notes for begin and end
				begin - always the furthest back in time
				end - always the most recent in time

		</xsd:documentation>
	</xsd:annotation>
	<xsd:annotation>
		<xsd:documentation>*** LICENSE INFORMATION *****
		Copyright 2002, 2003 DLESE Program Center
		University Corporation for Atmospheric Research (UCAR)
		P.O. Box 3000, Boulder, CO 80307, United States of America
		email: support@dlese.org. 
These schemas are free software; you can redistribute them and/or modify them under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.  These schemas are distributed in the hope that they will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this project; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA  
		</xsd:documentation>
	</xsd:annotation>
	<xsd:annotation>
		<xsd:documentation>***********************  Other CATEGORY Schemas to Include  ********************************</xsd:documentation>
	</xsd:annotation>
	<xsd:include schemaLocation="commonfields.xsd"/>
	<xsd:annotation>
		<xsd:documentation>************************  VOCABULARY Schemas to Include  ***********************************</xsd:documentation>
	</xsd:annotation>
	<xsd:include schemaLocation="../vocabs/timeUnits.xsd"/>
	<xsd:annotation>
		<xsd:documentation>************************  ROOT Element  **********************************************
							There is no root element for this schema.
		</xsd:documentation>
	</xsd:annotation>
	<xsd:annotation>
		<xsd:documentation>************************  Complex Types  (alpha order) *****************************
	
				ADType		  					is part of timeADType
				pastType						is part of timePastType
				periodType						is part of periodsType
				periodsType					is part of timeAndPeriodType
				temporalCoveragesType  		is part of ADNmetdataType in record.xsd
				timeADType						is part of timeInfoType
				timeAndPeriodType				is part of temporalCoveragesType
				timeBCType						is part of timeInfoType
				timeInfoType 					is part of timeAndPeriodType
				timeRelativeType				is part of timeInfoType
		</xsd:documentation>
	</xsd:annotation>
	<xsd:complexType name="ADType">
		<xsd:annotation>
			<xsd:documentation>
				************   ADType  **************************************
				These elements have the following types or schema associated with them.
				date				is an attribute
				time				is an attribute
			</xsd:documentation>
		</xsd:annotation>
		<xsd:simpleContent>
			<xsd:extension base="xsd:string">
				<xsd:attribute name="date" type="union.dateType" use="required"/>
				<xsd:attribute name="time" type="xsd:time" use="optional"/>
			</xsd:extension>
		</xsd:simpleContent>
	</xsd:complexType>
	<xsd:complexType name="periodType">
		<xsd:annotation>
			<xsd:documentation>
				************   periodType  **************************************
				These elements have the following types or schema associated with them.
				name			is a global; see commonfields.xsd
				source			is a global; see commonfields.xsd
				IDandURL		is complex; see commonfields.xsd
				sourceDescr	is a global; see commonfields.xsd
			</xsd:documentation>
		</xsd:annotation>
		<xsd:all>
			<xsd:element ref="name" minOccurs="1" maxOccurs="1"/>
			<xsd:element ref="source" minOccurs="1" maxOccurs="1"/>
			<xsd:element name="IDandURL" type="IDandURLType" minOccurs="0" maxOccurs="1"/>
			<xsd:element ref="sourceDesc" minOccurs="0" maxOccurs="1"/>
		</xsd:all>
	</xsd:complexType>
	<xsd:complexType name="periodsType">
		<xsd:annotation>
			<xsd:documentation>
				************   periodsType  **************************************
				These elements have the following types or schema associated with them.
				period				is complex
			</xsd:documentation>
		</xsd:annotation>
		<xsd:sequence>
			<xsd:element name="period" type="periodType" minOccurs="1" maxOccurs="unbounded"/>
		</xsd:sequence>
	</xsd:complexType>
	<xsd:complexType name="relativeType">
		<xsd:annotation>
			<xsd:documentation>
				******************   relativeType  **************************************
				These elements have the following types or schema associated with them.
				units			is an attribute; see timeUnits.xsd
			</xsd:documentation>
		</xsd:annotation>
		<xsd:simpleContent>
			<xsd:extension base="relativeNumberType">
				<xsd:attribute name="units" type="timeUnitsType" use="required"/>
			</xsd:extension>
		</xsd:simpleContent>
	</xsd:complexType>
	<xsd:complexType name="temporalCoveragesType">
		<xsd:annotation>
			<xsd:documentation>
				************   temporalCoverages Type  **************************************
				temporalType is the root element for this schema.
				These elements have the following types or schema associated with them.
				timeAndPeriod			is complex
			</xsd:documentation>
		</xsd:annotation>
		<xsd:sequence>
			<xsd:element name="timeAndPeriod" type="timeAndPeriodType" minOccurs="1" maxOccurs="unbounded"/>
		</xsd:sequence>
	</xsd:complexType>
	<xsd:complexType name="timeADType">
		<xsd:annotation>
			<xsd:documentation>
				************   timeADType  **************************************
				These elements have the following types or schema associated with them.
				begin				is complex
				end					is complex
			</xsd:documentation>
		</xsd:annotation>
		<xsd:sequence>
			<xsd:element name="begin" type="ADType" minOccurs="1" maxOccurs="1"/>
			<xsd:element name="end" type="ADType" minOccurs="1" maxOccurs="1"/>
		</xsd:sequence>
	</xsd:complexType>
	<xsd:complexType name="timeAndPeriodType">
		<xsd:annotation>
			<xsd:documentation>
				************   timeAndPeriod Type  **************************************
				These elements have the following types or schema associated with them.
				timeInfo				is complex
				periodInfo			is complex
			</xsd:documentation>
		</xsd:annotation>
		<xsd:all>
			<xsd:element name="timeInfo" type="timeInfoType" minOccurs="1" maxOccurs="1"/>
			<xsd:element name="periods" type="periodsType" minOccurs="0" maxOccurs="1"/>
		</xsd:all>
	</xsd:complexType>
	<xsd:complexType name="timeBCType">
		<xsd:annotation>
			<xsd:documentation>
				************   timeBCType  **************************************
				These elements have the following types or schema associated with them.
				begin				is a simple derived type gYear refers to an actual year; e.g -0357 with 4 digits as a minimum
				begin				is furthest back in time
				end					is a simpe derived; type gYear refers to an acutal year; e.g -0046 with 4 digits as a minimum
				end					is the most recent in time
			</xsd:documentation>
		</xsd:annotation>
		<xsd:sequence>
			<xsd:element name="begin" type="BCType" minOccurs="1" maxOccurs="1" nillable="false"/>
			<xsd:element name="end" type="BCType" minOccurs="1" maxOccurs="1" nillable="false"/>
		</xsd:sequence>
	</xsd:complexType>
	<xsd:complexType name="timeInfoType">
		<xsd:annotation>
			<xsd:documentation>
				************   timeInfoType  **************************************
				These elements have the following types or schema associated with them.
				timeAD				is complex
				timeBC				is complex
				timeRelative			is complex
			</xsd:documentation>
		</xsd:annotation>
		<xsd:choice minOccurs="1" maxOccurs="1">
			<xsd:element name="timeAD" type="timeADType" minOccurs="1" maxOccurs="1"/>
			<xsd:element name="timeBC" type="timeBCType" minOccurs="1" maxOccurs="1"/>
			<xsd:element name="timeRelative" type="timeRelativeType" minOccurs="1" maxOccurs="1"/>
		</xsd:choice>
	</xsd:complexType>
	<xsd:complexType name="timeRelativeType">
		<xsd:annotation>
			<xsd:documentation>
				************   timeRelative Type  **************************************
				These elements have the following types or schema associated with them.
				begin				is complex
				end					is complex
			</xsd:documentation>
		</xsd:annotation>
		<xsd:sequence>
			<xsd:element name="begin" type="relativeType" minOccurs="1" maxOccurs="1" nillable="false"/>
			<xsd:element name="end" type="relativeType" minOccurs="1" maxOccurs="1" nillable="false"/>
		</xsd:sequence>
	</xsd:complexType>
	<xsd:annotation>
		<xsd:documentation>***********************  Simple Types (alpha order) *************************************
				BCType							is used in timeBCType
				endADType						is used in timeADType
				relativeNumberType				is used in relativeType

		</xsd:documentation>
	</xsd:annotation>
	<xsd:simpleType name="BCType">
		<xsd:annotation>
			<xsd:documentation>
				************   BC Type  **************************************
				- Ensures that null content is not accepted for the begin and end tags for the timeBCType
				- Type gYear refers to an actual year; e.g -0357 with 4 digits as a minimum
				- Since begin and end are to be before 0000 AD, the maxinclusive value has been set to 0001
			</xsd:documentation>
		</xsd:annotation>
		<xsd:restriction base="xsd:gYear">
			<xsd:maxInclusive value="-0001"/>
		</xsd:restriction>
	</xsd:simpleType>
	<xsd:simpleType name="relativeNumberType">
		<xsd:annotation>
			<xsd:documentation>
				************   relativeNumberType  **************************************
				Ensures that null content is not accepted for the begin and end tags for the timePastType
				0.0 is allowed in order to represent concepts like 30 days ago to present
			</xsd:documentation>
		</xsd:annotation>
		<xsd:restriction base="xsd:decimal">
			<xsd:minInclusive value="0.0"/>
		</xsd:restriction>
	</xsd:simpleType>
</xsd:schema>

