Saxon

<?xml version="1.0"?>

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"

           elementFormDefault="qualified">

    <xs:element name="meeting">

        <xs:complexType>

            <xs:sequence>

                <xs:element name="start-time" type="xs:time" />

                <xs:element name="end-time" type="xs:time" />

                <xs:element name="room-number" type="xs:string" />

            </xs:sequence>

        </xs:complexType>

    </xs:element>

    <xs:element name="calendar">

        <xs:complexType>

            <xs:sequence>

                <xs:element ref="meeting" maxOccurs="unbounded" />

            </xs:sequence>

        </xs:complexType>

    </xs:element>

</xs:schema>