<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="example" >
  <xs:complexType>
    <xs:sequence maxOccurs="unbounded">
       <xs:any />
    </xs:sequence>
  </xs:complexType>
</xs:element>

<xs:element name="unionTest" type="intervalOrDate" />

<xs:simpleType name="intervalOrDate" > 
  <xs:union>
    <xs:simpleType> 
       <xs:restriction base="interval" /> 
    </xs:simpleType>
    <xs:simpleType> 
       <xs:restriction base="xs:date" /> 
    </xs:simpleType>
  </xs:union>
</xs:simpleType>

<!-- here is a simple type that defines allowed values of the form "1d",
     "23h", etc." -->
<xs:simpleType name="interval" >
  <xs:restriction base="xs:string" >
     <xs:pattern value="[1-9][0-9]*d|[1-9][0-9]*h" />
  </xs:restriction>
</xs:simpleType> 

</xs:schema>
