XML/XML Schema/duration

using durations and define

File: Data.xml
<?xml version="1.0"?>
<data xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://www.wbex.ru Schema.xsd"
              xmlns="http://www.wbex.ru"
              >
   P4M    
</data>
File: Schema.xsd

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://www.wbex.ru" xmlns="http://www.wbex.ru"
  elementFormDefault="qualified">
  
    <xsd:element name="data" type="myDuration"/>
  
  <xsd:simpleType name="myDuration">
    <xsd:restriction base="xsd:duration">
      <xsd:minInclusive value="P3M" />
    </xsd:restriction>
  </xsd:simpleType>
</xsd:schema>

xs:maxInclusive defines a maximum value that can be reached based on xs:duration

File: Data.xml
<?xml version="1.0"?>
<data xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://www.wbex.ru Schema.xsd"
              xmlns="http://www.wbex.ru"
              >
   P1M    
</data>
File: Schema.xsd
<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://www.wbex.ru" xmlns="http://www.wbex.ru"
  elementFormDefault="qualified">
    <xsd:element name="data" type="myDuration"/>

  <xsd:simpleType name="myDuration">
    <xsd:restriction base="xsd:duration">
      <xsd:maxInclusive value="P3M" />
    </xsd:restriction>
  </xsd:simpleType>
</xsd:schema>