diff --git a/ChangeLog b/ChangeLog
index 85c4219707..0dd40026c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Jun 30 21:51:40 2017  Marcus Stollsteimer  <sto.mar@web.de>
+
+	* ext/date/date_core.c: [DOC] fix documentation for %Z format of
+	  {Date,DateTime}.strftime.
+	  Reported by Damon Timm. Based on a patch by nano.
+	  [Bug #13231] [Fix GH-1565]
+
 Fri Jun 30 21:46:50 2017  Kouhei Sutou  <kou@cozmixng.org>
 
 	* lib/rss/rss.rb: Accept empty text element as valid element
diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index 611279c8d2..0a7e6f15cb 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -6787,7 +6787,7 @@ date_strftime_internal(int argc, VALUE *argv, VALUE self,
  *              %::z - hour, minute and second offset from UTC (e.g. +09:00:00)
  *              %:::z - hour, minute and second offset from UTC
  *                                                (e.g. +09, +09:30, +09:30:30)
- *      %Z - Time zone abbreviation name or something similar information.
+ *      %Z - Equivalent to %:z (e.g. +09:00)
  *
  *    Weekday:
  *      %A - The full weekday name (``Sunday'')
@@ -8218,7 +8218,7 @@ dt_lite_to_s(VALUE self)
  *              %::z - hour, minute and second offset from UTC (e.g. +09:00:00)
  *              %:::z - hour, minute and second offset from UTC
  *                                                (e.g. +09, +09:30, +09:30:30)
- *      %Z - Time zone abbreviation name or something similar information.
+ *      %Z - Equivalent to %:z (e.g. +09:00)
  *
  *    Weekday:
  *      %A - The full weekday name (``Sunday'')
diff --git a/version.h b/version.h
index 2c66fdd18c..ed33160a9a 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.5"
 #define RUBY_RELEASE_DATE "2017-06-30"
-#define RUBY_PATCHLEVEL 333
+#define RUBY_PATCHLEVEL 334
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 6