diff --git a/ext/pim.calendar/native/timezone_utils.cpp b/ext/pim.calendar/native/timezone_utils.cpp
index 0f95992d..17c813fc 100644
--- a/ext/pim.calendar/native/timezone_utils.cpp
+++ b/ext/pim.calendar/native/timezone_utils.cpp
@@ -41,7 +41,7 @@ int TimezoneUtils::offsetFromUtcToTz(QDateTime date, QString timezoneId, bool ig
         *error = true;
         return 0;
     }
-    cal->set(date.date().year(), date.date().month(), date.date().day(), date.time().hour(), date.time().minute());
+    cal->set(date.date().year(), date.date().month()-1, date.date().day(), date.time().hour(), date.time().minute());
     UDate udate = cal->getTime(errorCode);
     if (errorCode > 0) {
         *error = true;