VS2008: Running xsd.exe on schema file gives XMLSchema:datetime is not declared

<xs:schema id="Appointment" targetNamespace="http://tempuri.org/Record.xsd" elementFormDefault="qualified"
attributeFormDefault="qualified" xmlns="http://tempuri.org/Record.xsd" xmlns:mstns="http://tempuri.org/Record.xsd"
xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xs:element name="Record" msdata:IsDataSet="true">
	<xs:complexType>
		<xs:choice maxOccurs="unbounded">
			<xs:element name="Record">
				<xs:complexType>
					<xs:sequence>
						<xs:element name="ID" type="xs:string" minOccurs="0" />
						<xs:element name="TimeStart" type="xs:datetime" minOccurs="0" />
						<xs:element name="TimeEnd" type="xs:datetime" minOccurs="0" />
					</xs:sequence>
				</xs:complexType>
			</xs:element>
		</xs:choice>
	</xs:complexType>
</xs:element>

Schema validation warning: Type 'http://www.w3.org/2001/XMLSchema:datetime' is not declared. Line 13, position 9.

xs:dateTime

xs:datetime