diff --git a/build/test_master_unsigned.xsl b/build/test_master_unsigned.xsl
index 769e13fb..77392294 100644
--- a/build/test_master_unsigned.xsl
+++ b/build/test_master_unsigned.xsl
@@ -33,7 +33,7 @@
 		This parameter determines the number of days between the aggregation instant and the
 		end of validity of the signed metadata.
 	-->
-	<xsl:variable name="validityDays" select="14"/>
+	<xsl:variable name="validityDays" select="21"/>
 	
 	<xsl:variable name="now" select="date:date-time()"/>
 	<xsl:variable name="validUntil" select="mdxDates:dateAdd($now, $validityDays)"/>
diff --git a/build/uk_master_back.xsl b/build/uk_master_back.xsl
index 4f03d769..2bf5bb79 100644
--- a/build/uk_master_back.xsl
+++ b/build/uk_master_back.xsl
@@ -39,7 +39,7 @@
 		This parameter determines the number of days between the aggregation instant and the
 		end of validity of the signed metadata.
 	-->
-	<xsl:variable name="validityDays" select="14"/>
+	<xsl:variable name="validityDays" select="21"/>
 	
 	<xsl:variable name="now" select="date:date-time()"/>
 	<xsl:variable name="validUntil" select="mdxDates:dateAdd($now, $validityDays)"/>
diff --git a/build/uk_master_export.xsl b/build/uk_master_export.xsl
index 689f01a9..5f128dbd 100644
--- a/build/uk_master_export.xsl
+++ b/build/uk_master_export.xsl
@@ -40,7 +40,7 @@
 		This parameter determines the number of days between the aggregation instant and the
 		end of validity of the signed metadata.
 	-->
-	<xsl:variable name="validityDays" select="14"/>
+	<xsl:variable name="validityDays" select="21"/>
 	
 	<xsl:variable name="now" select="date:date-time()"/>
 	<xsl:variable name="validUntil" select="mdxDates:dateAdd($now, $validityDays)"/>
diff --git a/build/uk_master_test.xsl b/build/uk_master_test.xsl
index eb90f15c..977d116d 100644
--- a/build/uk_master_test.xsl
+++ b/build/uk_master_test.xsl
@@ -42,7 +42,7 @@
 		This parameter determines the number of days between the aggregation instant and the
 		end of validity of the signed metadata.
 	-->
-	<xsl:variable name="validityDays" select="14"/>
+	<xsl:variable name="validityDays" select="21"/>
 	
 	<xsl:variable name="now" select="date:date-time()"/>
 	<xsl:variable name="validUntil" select="mdxDates:dateAdd($now, $validityDays)"/>
diff --git a/build/uk_master_unsigned.xsl b/build/uk_master_unsigned.xsl
index 33e27838..35036414 100644
--- a/build/uk_master_unsigned.xsl
+++ b/build/uk_master_unsigned.xsl
@@ -39,7 +39,7 @@
 		This parameter determines the number of days between the aggregation instant and the
 		end of validity of the signed metadata.
 	-->
-	<xsl:variable name="validityDays" select="14"/>
+	<xsl:variable name="validityDays" select="21"/>
 	
 	<xsl:variable name="now" select="date:date-time()"/>
 	<xsl:variable name="validUntil" select="mdxDates:dateAdd($now, $validityDays)"/>