diff --git a/Tests/xdiffTest.php b/Tests/xdiffTest.php
index 9e61f0b..3a8a849 100644
--- a/Tests/xdiffTest.php
+++ b/Tests/xdiffTest.php
@@ -181,8 +181,10 @@ to this document.
     $xdiff = new xdiff ("unified");
     $res = $xdiff->diff ($this->string1, $this->string2);
     $date = date ("Y-m-d H:i:s.u00");
-    $this->assertSame ($res, "--- Original ${date}0 +0100
-+++ New ${date}1 +0100
+    // DST must answer +0200 in winter and +0100 in summer
+    $dst = date ("O");
+    $this->assertSame ($res, "--- Original ${date}0 $dst
++++ New ${date}1 $dst
 @@ -0,0 +1,6 @@
 +This is an important
 +notice! It should