Calculate Years, Months, weeks and Days

Question

In my application, a user enters two dates. A scheduled start date, and a scheduled end date. We have to take those dates, and populate 4 fields, based on the difference.

Answer 1

I had created this one for returning difference in years,month and days between 2 dates.

public static Dictionary TimeSpanToDateParts(DateTime fromDate,DateTime toDate)
        {
            int years;
            int months;
            int days;
            Dictionary dateParts = new Dictionary();
            if (toDate < fromDate)
            {
               return TimeSpanToDateParts(toDate,fromDate);
            }

            var span = toDate - fromDate;

            months = 12 * (toDate.Year - fromDate.Year) + (toDate.Month - fromDate.Month);

            if (toDate.CompareTo(fromDate.AddMonths(months).AddMilliseconds(-500)) <= 0)
            {
                --months;
            }

            years = months / 12;
            months -= years * 12;

            if (months == 0 && years == 0)
            {
                days = span.Days;
            }
            else
            {
                days = toDate.Day;
                if (fromDate.Day > toDate.Day)
                    days = days + (DateTime.DaysInMonth(toDate.Year, toDate.Month - 1) - fromDate.Day);
                else
                    days = days - fromDate.Day;
            }
            dateParts.Add("Years", years);
            dateParts.Add("Months", months);
            dateParts.Add("Days", days);

            return dateParts;
        }