XML Tutorial/XML Schema/timeDuration

A gestation period of about three and a half months.

File: Schema.xsd
<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://www.wbex.ru" xmlns="http://www.wbex.ru"
  elementFormDefault="qualified">
  <xs:element name="gestation" type="xs:timeDuration" />
</xs:schema>

File: Data.xml
<?xml version="1.0"?>
<gestation xmlns="http://www.wbex.ru">P3M15D</gestation>
Notice that you don"t have to specify all of the units. 
Only the initial P is always required. 
If the period contains time data, you must also add the T.