Metodo DateDiff in C#

public static long DateDiff(DateInterval interval, DateTime startDate, DateTime endDate)

{

	long dateDiffVal = 0;

	TimeSpan ts = new TimeSpan(endDate.Ticks - startDate.Ticks);

	switch(interval)

	{

		case DateInterval.Day:

			dateDiffVal = (long)ts.Days;

			break;

		case DateInterval.Hour:

			dateDiffVal = (long)ts.TotalHours;

			break;

		case DateInterval.Millisecond:

			dateDiffVal = (long)ts.TotalMilliseconds;

			break;

		case DateInterval.Minute:

			dateDiffVal = (long)ts.TotalMinutes;

			break;

		case DateInterval.Month:

			dateDiffVal = (long)(ts.Days / 30);

			break;

		case DateInterval.Quarter:

			dateDiffVal = (long)((ts.Days / 30) / 3);

			break;

		case DateInterval.Second:

			dateDiffVal = (long)ts.TotalSeconds;

			break;

		case DateInterval.Week:

			dateDiffVal = (long)(ts.Days / 7);

			break;

		case DateInterval.Year:

			dateDiffVal = (long)(ts.Days / 365);

			break;

	}

	return dateDiffVal;

}

public enum DateInterval

{

	Millisecond,

	Second,

	Minute,

	Hour,

	Day,

	Week,

	Month,

	Quarter,

	Year,

}