diff --git a/WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml b/WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml
new file mode 100644
index 0000000000..9c7a2ffabc
--- /dev/null
+++ b/WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml
@@ -0,0 +1,44 @@
+<documentation title="Restricted Date and Time Functions">
+    <standard>
+        <![CDATA[
+      The restricted functions date_default_timezone_set() and date() should not be used.
+
+      Using date_default_timezone_set() isn't allowed, because WordPress core needs default time zone set to UTC. Use DateTime object or WP core API functions instead.
+
+      Using date() isn't allowed, as it is affected by runtime timezone changes which can cause date/time to be incorrectly displayed. Use gmdate() instead.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Using DateTime object.">
+            <![CDATA[
+$date = new DateTime();
+$date->setTimezone(
+    new DateTimeZone( 'Europe/Amsterdam' )
+);
+        ]]>
+        </code>
+        <code title="Invalid: Using date_default_timezone_set().">
+            <![CDATA[
+date_default_timezone_set( 'Europe/Amsterdam' );
+        ]]>
+        </code>
+    </code_comparison>
+    <code_comparison>
+        <code title="Valid: Using gmdate().">
+            <![CDATA[
+$last_updated = gmdate(
+    'Y-m-d\TH:i:s',
+    strtotime( $plugin['last_updated'] )
+);
+        ]]>
+        </code>
+        <code title="Invalid: Using date().">
+            <![CDATA[
+$last_updated = date(
+    'Y-m-d\TH:i:s',
+    strtotime( $plugin['last_updated'] )
+);
+        ]]>
+        </code>
+    </code_comparison>
+</documentation>
diff --git a/WordPress/Docs/WP/TimezoneChangeStandard.xml b/WordPress/Docs/WP/TimezoneChangeStandard.xml
deleted file mode 100644
index 08ed87f6b6..0000000000
--- a/WordPress/Docs/WP/TimezoneChangeStandard.xml
+++ /dev/null
@@ -1,22 +0,0 @@
-<documentation title="Disallow the changing of timezone.">
-    <standard>
-    <![CDATA[
-      Using date_default_timezone_set() and similar isn't allowed, instead use WP internal timezone support.
-    ]]>
-    </standard>
-    <code_comparison>
-        <code title="Valid: Using WP internal timezone support.">
-        <![CDATA[
-$date = new DateTime();
-$date->setTimezone(
-    new DateTimeZone( 'America/Toronto' )
-);
-        ]]>
-        </code>
-        <code title="Invalid: date_default_timezone_set() is used.">
-        <![CDATA[
-date_default_timezone_set( 'Foo/Bar' );
-        ]]>
-        </code>
-    </code_comparison>
-</documentation>