Relational operators

Times can be tested for equality and for the obvious ordering relation. For example,

      Time::julian(1988,1)  > Time::julian(1988,1)-
                                    Duration::seconds(1)
      Time::julian(1988,1)  < Time::julian(1988,1)+
                                    Duration::seconds(1)
      Time::julian(1988,1) == Time::Time(1988,
                                         Time::january,1);