diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..18171b9
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "xml-schemas/ebu-tt-m-xsd"]
+	path = xml-schemas/ebu-tt-m-xsd
+	url = https://github.com/ebu/ebu-tt-m-xsd.git
diff --git a/xml-schemas/README.md b/xml-schemas/README.md
index 83995e0..9a99faf 100644
--- a/xml-schemas/README.md
+++ b/xml-schemas/README.md
@@ -12,9 +12,10 @@ schema document.
 
 ## Design
 
-The DAPT XSD is designed to be inclusive, rather than defining attributes and elements from the DAPT specification
+The DAPT XSD is designed to be inclusive of all content predicted from the DAPT specification,
+rather than defining attributes and elements from the DAPT specification
 and relying on external XSDs for other namespace vocabulary.
-This is so that DAPT-specific constraints, such as the prohibition of the `<animation>` element,
+This also permits DAPT-specific constraints, such as the prohibition of the `<animation>` element,
 or the requirement for the `daptm:scriptRepresents` attribute on the root `<tt>` element,
 can be applied.
 
@@ -27,6 +28,9 @@ However it also simplifies usage.
 
 Additionally, DAPT namespaces and DAPT-specific data types are defined in imported files whose name is prefixed `dapt-`.
 
+EBU-TT Metadata is imported via a git submodule pointed at the XSD 1 version of the
+[EBU-TT Metadata schema](https://github.com/ebu/ebu-tt-m-xsd/tree/issue-0030-schema-v1).
+
 ### Implicit (namespace-based) references to dependent XSDs
 
 A [`dapt-all.xsd`](dapt-all.xsd) is provided for XSD tools that allow for implicit references to schema documents
diff --git a/xml-schemas/dapt-metadata.xsd b/xml-schemas/dapt-metadata.xsd
index 3f0d0fe..09b0892 100644
--- a/xml-schemas/dapt-metadata.xsd
+++ b/xml-schemas/dapt-metadata.xsd
@@ -2,21 +2,15 @@
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"
      version="2024-11-13" attributeFormDefault="qualified"
      targetNamespace="http://www.w3.org/ns/ttml/profile/dapt#metadata"
-     xmlns:daptd="http://www.w3.org/ns/ttml/profile/dapt#datatype">
+     xmlns:daptd="http://www.w3.org/ns/ttml/profile/dapt#datatype"
+     xmlns:daptm="http://www.w3.org/ns/ttml/profile/dapt#metadata">
      <xs:import namespace="http://www.w3.org/ns/ttml/profile/dapt#datatype"
           schemaLocation="dapt-datatypes.xsd"/>
-     <xs:attribute name="scriptType">
+     <xs:attribute name="descType">
           <xs:simpleType>
-               <xs:restriction base="xs:token">
-                    <xs:enumeration value="originalTranscript"/>
-                    <xs:enumeration value="translatedTranscript"/>
-                    <xs:enumeration value="preRecording"/>
-                    <xs:enumeration value="asRecorded"/>
-               </xs:restriction>
+               <xs:restriction base="xs:string"/>
           </xs:simpleType>
      </xs:attribute>
-     <xs:attribute name="scriptRepresents" type="daptd:contentDescriptorType"/>
-     <xs:attribute name="represents" type="daptd:contentDescriptorType"/>
      <xs:attribute name="langSrc">
           <xs:simpleType>
                <xs:restriction base="xs:language"/>
@@ -32,9 +26,28 @@
                </xs:restriction>
           </xs:simpleType>
      </xs:attribute>
-     <xs:attribute name="descType">
+     <xs:attribute name="represents" type="daptd:contentDescriptorType"/>
+     <xs:attribute name="scriptRepresents" type="daptd:contentDescriptorType"/>
+     <xs:attribute name="scriptType">
           <xs:simpleType>
-               <xs:restriction base="xs:string"/>
+               <xs:restriction base="xs:token">
+                    <xs:enumeration value="originalTranscript"/>
+                    <xs:enumeration value="translatedTranscript"/>
+                    <xs:enumeration value="preRecording"/>
+                    <xs:enumeration value="asRecorded"/>
+               </xs:restriction>
           </xs:simpleType>
      </xs:attribute>
+     <xs:element name="daptOriginTimecode">
+          <xs:simpleType>
+               <xs:restriction base="xs:string">
+                    <xs:pattern value="\d[\d]+:\d\d:\d\d:\d\d"></xs:pattern>
+               </xs:restriction>
+          </xs:simpleType>
+     </xs:element>
+     <xs:group name="Metadata.class">
+          <xs:choice>
+               <xs:element ref="daptm:daptOriginTimecode"/>
+          </xs:choice>
+     </xs:group>
 </xs:schema>
diff --git a/xml-schemas/dapt.xsd b/xml-schemas/dapt.xsd
index d23ab24..90e0fc2 100644
--- a/xml-schemas/dapt.xsd
+++ b/xml-schemas/dapt.xsd
@@ -4,6 +4,7 @@
     xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning"
     xmlns:xs="http://www.w3.org/2001/XMLSchema"
     xmlns:daptm="http://www.w3.org/ns/ttml/profile/dapt#metadata"
+    xmlns:ebuttm="urn:ebu:tt:metadata"
     xmlns:tt="http://www.w3.org/ns/ttml"
     xmlns:ttm="http://www.w3.org/ns/ttml#metadata"
     xmlns:ttp="http://www.w3.org/ns/ttml#parameter"
@@ -14,6 +15,8 @@
         schemaLocation="ttml2-metadata-items.xsd"/>
     <xs:import namespace="http://www.w3.org/ns/ttml/profile/dapt#metadata"
         schemaLocation="dapt-metadata.xsd"/>
+    <xs:import namespace="urn:ebu:tt:metadata"
+        schemaLocation="ebu-tt-m-xsd/ebu-tt-metadata.xsd"/>
     <xs:import namespace="http://www.w3.org/ns/ttml#parameter"
         schemaLocation="ttml2-parameter-items.xsd"/>
     <xs:import namespace="http://www.w3.org/ns/ttml#styling"
diff --git a/xml-schemas/ebu-tt-m-xsd b/xml-schemas/ebu-tt-m-xsd
new file mode 160000
index 0000000..4026249
--- /dev/null
+++ b/xml-schemas/ebu-tt-m-xsd
@@ -0,0 +1 @@
+Subproject commit 4026249a949f594ae0d38b84e22cf2e8e665f235