diff --git a/jni/timer.c b/jni/timer.c
index 23cef3a..dc4dea2 100644
--- a/jni/timer.c
+++ b/jni/timer.c
@@ -210,9 +210,9 @@ set_accesstime()
   (void)time(&gmt);
   ltm = localtime(&gmt);
 #ifdef SYSV_TIME
-  systime_offset += timezone;
-  if( ltm->tm_isdst > 0 )
-    systime_offset = -3600;
+  systime_offset = timezone;
+  if( ltm->tm_isdst )
+    systime_offset -= 3600;
 #else
   systime_offset = -ltm->tm_gmtoff;
 #endif