void operator<<(LexicalConverter &, const TimeDelta &);
+
+// Constants to be used in creation of TimeDeltas
+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;
+
} // namespace Time
} // namespace Msp