diff --git a/DateTimeCore.cpp b/DateTimeCore.cpp
index 6dade96..37d130f 100644
--- a/DateTimeCore.cpp
+++ b/DateTimeCore.cpp
@@ -309,7 +309,8 @@ bool ReadDateTime( const char * DateTimeStr, bool LocalTime, time_t &EpochTime )
     // Update time
     NewTime.tm_year -= 1900;
     NewTime.tm_mon  -= 1;
-    NewTime.tm_zone = "UTC";
+    NewTime.tm_zone  = "UTC";
+    NewTime.tm_isdst = -1;
 
     // Convert to Epoch Time
     EpochTime = mktime( &NewTime ) + ((LocalTime)? 0 : NewTime.tm_gmtoff);