def __sub__(self, subtrahend):
if isinstance(subtrahend, datetime.timedelta):<EOL><INDENT>return Time.fromDatetime(self._time - subtrahend)<EOL><DEDENT>if isinstance(subtrahend, Time):<EOL><INDENT>return self.asDatetime() - subtrahend.asDatetime()<EOL><DEDENT>return NotImplemented<EOL>
Implement subtraction of an interval or another time from this one.

@type subtrahend: L{datetime.timedelta} or L{Time}

@param subtrahend: The object to be subtracted from this one.

@rtype: L{datetime.timedelta} or L{Time}

@return: If C{subtrahend} is a L{datetime.timedelta}, the result is
a L{Time} instance which is offset from this one by that amount.  If
C{subtrahend} is a L{Time}, the result is a L{datetime.timedelta}
instance which gives the difference between it and this L{Time}
instance.