+MSPCORE_API void operator<<(LexicalConverter &, const TimeDelta &);
+
+
+// Constants to be used in creation of TimeDeltas
+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;
+
+inline TimeDelta abs(const TimeDelta &t) { return t>=zero ? t : -t; }
+using std::abs;