Ticket #48384: 48384-fixed-utc-time-slipping-on-time-zone-change.patch

tests/phpunit/tests/date/postTime.php

@@ -62 +62 @@
                 $this->assertEquals( $rfc3339, get_post_modified_time( DATE_RFC3339, false, $post_id, true ) );
                 $this->assertEquals( $rfc3339_utc, get_post_modified_time( DATE_RFC3339, true, $post_id, true ) );
         }
+
+        /**
+         * @ticket 48384
+         */
+        public function test_should_keep_utc_time_on_timezone_change() {
+
+                $timezone = 'UTC';
+                update_option( 'timezone_string', $timezone );
+                $datetime = new DateTimeImmutable( 'now', new DateTimeZone( $timezone ) );
+                $mysql    = $datetime->format( 'Y-m-d H:i:s' );
+                $rfc3339  = $datetime->format( DATE_RFC3339 );
+                $post_id  = self::factory()->post->create(
+                        array(
+                                'post_date'     => $mysql,
+                                'post_modified' => $mysql,
+                        )
+                );
+
+                update_option( 'timezone_string', 'Europe/Kiev' );
+
+                $this->assertEquals( $rfc3339, get_post_time( DATE_RFC3339, true, $post_id ) );
+                $this->assertEquals( $rfc3339, get_post_modified_time( DATE_RFC3339, true, $post_id ) );
+        }
 }

src/wp-includes/general-template.php

@@ -2565 +2565 @@
                 return false;
         }
 
-        $datetime = get_post_datetime( $post );
+        $source   = ( $gmt ) ? 'gmt' : 'local';
+        $datetime = get_post_datetime( $post, 'date', $source );
 
         if ( false === $datetime ) {
                 return false;
@@ -2606 +2607 @@
  *
  * The object will be set to the timezone from WordPress settings.
  *
+ * For legacy reasons this function allows to choose to instance from local or UTC time in database.
+ * Normally this should make no difference to result. However the values might get out of sync in database,
+ * typically because of time zone setting changed. The parameter ensures ability to reproduce backwards
+ * compatible behaviors in such cases.
+ *
  * @since 5.3.0
  *
- * @param int|WP_Post $post  Optional. WP_Post object or ID. Default is global `$post` object.
- * @param string      $field Optional. Post field to use. Accepts 'date' or 'modified'.
+ * @param int|WP_Post $post   Optional. WP_Post object or ID. Default is global `$post` object.
+ * @param string      $field  Optional. Published or modified time to use from database. Accepts 'date' or 'modified'.
+ * @param string      $source Optional. Local or UTC time to use from database. Accepts 'local' or 'gmt'.
+ *
  * @return DateTimeImmutable|false Time object on success, false on failure.
  */
-function get_post_datetime( $post = null, $field = 'date' ) {
+function get_post_datetime( $post = null, $field = 'date', $source = 'local' ) {
         $post = get_post( $post );
 
         if ( ! $post ) {
                 return false;
         }
 
-        $time = ( 'modified' === $field ) ? $post->post_modified : $post->post_date;
+        $wp_timezone = wp_timezone();
+
+        if ( 'gmt' === $source ) {
+                $time     = ( 'modified' === $field ) ? $post->post_modified_gmt : $post->post_date_gmt;
+                $timezone = new DateTimeZone( 'UTC' );
+        } else {
+                $time     = ( 'modified' === $field ) ? $post->post_modified : $post->post_date;
+                $timezone = $wp_timezone;
+        }
 
         if ( empty( $time ) || '0000-00-00 00:00:00' === $time ) {
                 return false;
         }
 
-        return date_create_immutable_from_format( 'Y-m-d H:i:s', $time, wp_timezone() );
+        $datetime = date_create_immutable_from_format( 'Y-m-d H:i:s', $time, $timezone );
+
+        if ( false === $datetime ) {
+                return false;
+        }
+
+        return $datetime->setTimezone( $wp_timezone );
 }
 
 /**
@@ -2729 +2751 @@
                 return false;
         }
 
-        $datetime = get_post_datetime( $post, 'modified' );
+        $source   = ( $gmt ) ? 'gmt' : 'local';
+        $datetime = get_post_datetime( $post, 'modified', $source );
 
         if ( false === $datetime ) {
                 return false;