diff --git a/sros2/sros2/policy/templates/dds/permissions.xsl b/sros2/sros2/policy/templates/dds/permissions.xsl
index e99f535a..6d20773f 100644
--- a/sros2/sros2/policy/templates/dds/permissions.xsl
+++ b/sros2/sros2/policy/templates/dds/permissions.xsl
@@ -6,8 +6,8 @@
  <xsl:output omit-xml-declaration="yes" indent="yes"/>
  <xsl:strip-space elements="*"/>
 
-<xsl:param name="not_valid_before" select="'2020-05-01T00:00:00'"/>
-<xsl:param name="not_valid_after" select="'2030-05-01T00:00:00'"/>
+<xsl:param name="not_valid_before" select="'2020-05-01T00:00:00Z'"/>
+<xsl:param name="not_valid_after" select="'2030-05-01T00:00:00Z'"/>
 
 <xsl:variable name="template_validity">
   <validity>
diff --git a/sros2/test/policies/permissions/add_two_ints/permissions.xml b/sros2/test/policies/permissions/add_two_ints/permissions.xml
index f8f5a6dc..5fce294f 100644
--- a/sros2/test/policies/permissions/add_two_ints/permissions.xml
+++ b/sros2/test/policies/permissions/add_two_ints/permissions.xml
@@ -3,8 +3,8 @@
     <grant name="/add_two_ints/add_two_ints_server">
       <subject_name>CN=/add_two_ints/add_two_ints_server</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -56,8 +56,8 @@
     <grant name="/add_two_ints/add_two_ints_client">
       <subject_name>CN=/add_two_ints/add_two_ints_client</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
diff --git a/sros2/test/policies/permissions/minimal_action/permissions.xml b/sros2/test/policies/permissions/minimal_action/permissions.xml
index be2153b1..6a14296f 100644
--- a/sros2/test/policies/permissions/minimal_action/permissions.xml
+++ b/sros2/test/policies/permissions/minimal_action/permissions.xml
@@ -3,8 +3,8 @@
     <grant name="/minimal_action/minimal_action_server">
       <subject_name>CN=/minimal_action/minimal_action_server</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -64,8 +64,8 @@
     <grant name="/minimal_action/minimal_action_client">
       <subject_name>CN=/minimal_action/minimal_action_client</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
diff --git a/sros2/test/policies/permissions/sample/permissions.xml b/sros2/test/policies/permissions/sample/permissions.xml
index 9400c4a8..63c1da10 100644
--- a/sros2/test/policies/permissions/sample/permissions.xml
+++ b/sros2/test/policies/permissions/sample/permissions.xml
@@ -3,8 +3,8 @@
     <grant name="/talker_listener/talker">
       <subject_name>CN=/talker_listener/talker</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -57,8 +57,8 @@
     <grant name="/talker_listener/listener">
       <subject_name>CN=/talker_listener/listener</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -111,8 +111,8 @@
     <grant name="/add_two_ints/add_two_ints_server">
       <subject_name>CN=/add_two_ints/add_two_ints_server</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -166,8 +166,8 @@
     <grant name="/add_two_ints/add_two_ints_client">
       <subject_name>CN=/add_two_ints/add_two_ints_client</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -221,8 +221,8 @@
     <grant name="/minimal_action/minimal_action_server">
       <subject_name>CN=/minimal_action/minimal_action_server</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -282,8 +282,8 @@
     <grant name="/minimal_action/minimal_action_client">
       <subject_name>CN=/minimal_action/minimal_action_client</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -343,8 +343,8 @@
     <grant name="/sample_policy/admin">
       <subject_name>CN=/sample_policy/admin</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
diff --git a/sros2/test/policies/permissions/single_context/permissions.xml b/sros2/test/policies/permissions/single_context/permissions.xml
index b54e3c56..8a325bd9 100644
--- a/sros2/test/policies/permissions/single_context/permissions.xml
+++ b/sros2/test/policies/permissions/single_context/permissions.xml
@@ -3,8 +3,8 @@
     <grant name="/single_enclave">
       <subject_name>CN=/single_enclave</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
diff --git a/sros2/test/policies/permissions/talker_listener/permissions.xml b/sros2/test/policies/permissions/talker_listener/permissions.xml
index 8f0b6166..34ef84a2 100644
--- a/sros2/test/policies/permissions/talker_listener/permissions.xml
+++ b/sros2/test/policies/permissions/talker_listener/permissions.xml
@@ -3,8 +3,8 @@
     <grant name="/talker_listener/talker">
       <subject_name>CN=/talker_listener/talker</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>
@@ -57,8 +57,8 @@
     <grant name="/talker_listener/listener">
       <subject_name>CN=/talker_listener/listener</subject_name>
       <validity>
-        <not_before>2020-05-01T00:00:00</not_before>
-        <not_after>2030-05-01T00:00:00</not_after>
+        <not_before>2020-05-01T00:00:00Z</not_before>
+        <not_after>2030-05-01T00:00:00Z</not_after>
       </validity>
       <allow_rule>
         <domains>