-extern const TimeDelta zero;
-extern const TimeDelta usec;
-extern const TimeDelta msec;
-extern const TimeDelta sec;
-extern const TimeDelta min;
-extern const TimeDelta hour;
-extern const TimeDelta day;
-extern const TimeDelta week;
+MSPCORE_API extern const TimeDelta zero;
+MSPCORE_API extern const TimeDelta usec;
+MSPCORE_API extern const TimeDelta msec;
+MSPCORE_API extern const TimeDelta sec;
+MSPCORE_API extern const TimeDelta min;
+MSPCORE_API extern const TimeDelta hour;
+MSPCORE_API extern const TimeDelta day;
+MSPCORE_API extern const TimeDelta week;