diff --git a/std/datetime.d b/std/datetime.d
index caeeb4d4c9b..e26515939e9 100644
--- a/std/datetime.d
+++ b/std/datetime.d
@@ -28622,7 +28622,7 @@ public:
             try
                 return to!string(tzname[1]);
             catch(Exception e)
-                assert(0, "to!string(tzname[0]) failed.");
+                assert(0, "to!string(tzname[1]) failed.");
         }
         else version(Windows)
         {