public ITimeSpan GetTimeHorizon()
        {
            DateTime modelStart = mohidLandEngine.GetStartInstant();
            DateTime modelEnd   = mohidLandEngine.GetStopInstant();

            double start = CalendarConverter.Gregorian2ModifiedJulian(modelStart);
            double end   = CalendarConverter.Gregorian2ModifiedJulian(modelEnd);

            ITimeStamp tStart = new Oatc.OpenMI.Sdk.Backbone.TimeStamp(start);
            ITimeStamp tEnd   = new TimeStamp(end);

            return(new Oatc.OpenMI.Sdk.Backbone.TimeSpan(tStart, tEnd));
        }