Itenso.TimePeriod.DateDiff.DateDiff C# (CSharp) Метод

        public DateDiff( DateTime date1, DateTime date2, Calendar calendar,
            DayOfWeek firstDayOfWeek, YearMonth yearBaseMonth = TimeSpec.CalendarYearStartMonth)
        {
            if ( calendar == null )
            {
                throw new ArgumentNullException( "calendar" );
            }
            this.calendar = calendar;
            this.yearBaseMonth = yearBaseMonth;
            this.firstDayOfWeek = firstDayOfWeek;
            this.date1 = date1;
            this.date2 = date2;
            difference = date2.Subtract( date1 );
        }