From 750cb11d78c42564708e3f16920557ad94fb841b Mon Sep 17 00:00:00 2001
From: Gary Jones <github@garyjones.io>
Date: Sat, 4 Jun 2022 11:11:49 +0100
Subject: [PATCH] Docs: Add TimezoneChange XML doc (#1731)

* Docs: Add TimezoneChange XML doc
---
 .../DateTime/RestrictedFunctionsStandard.xml  | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml

diff --git a/WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml b/WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml
new file mode 100644
index 0000000000..c8cc932cc9
--- /dev/null
+++ b/WordPress/Docs/DateTime/RestrictedFunctionsStandard.xml
@@ -0,0 +1,50 @@
+<documentation title="Restricted Date and Time Functions">
+    <standard>
+    <![CDATA[
+    The restricted functions date_default_timezone_set() and date() should not be used.
+    ]]>
+    </standard>
+    <standard>
+    <![CDATA[
+    Using the PHP native date_default_timezone_set() function isn't allowed, because WordPress Core needs the default time zone to be set to UTC for timezone calculations using the WP Core API to work correctly.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Using DateTime object.">
+        <![CDATA[
+$date = new <em>DateTime()</em>;
+$date->setTimezone(
+    new DateTimeZone( 'Europe/Amsterdam' )
+);
+        ]]>
+        </code>
+        <code title="Invalid: Using date_default_timezone_set().">
+        <![CDATA[
+<em>date_default_timezone_set</em>( 'Europe/Amsterdam' );
+        ]]>
+        </code>
+    </code_comparison>
+    <standard>
+    <![CDATA[
+    Using the PHP native date() function isn't allowed, as it is affected by runtime timezone changes which can cause the date/time to be incorrectly displayed. Use gmdate() instead.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Using gmdate().">
+        <![CDATA[
+$last_updated = <em>gmdate</em>(
+    'Y-m-d\TH:i:s',
+    strtotime( $plugin['last_updated'] )
+);
+        ]]>
+        </code>
+        <code title="Invalid: Using date().">
+        <![CDATA[
+$last_updated = <em>date</em>(
+    'Y-m-d\TH:i:s',
+    strtotime( $plugin['last_updated'] )
+);
+        ]]>
+        </code>
+    </code_comparison>
+</documentation>