protected DateTime NextCheckDate()

in src/log4net/Appender/RollingFileAppender.cs [1552:1615]
55 lines of code
8 McCabe index (conditional complexity)

		protected DateTime NextCheckDate(DateTime currentDateTime, RollPoint rollPoint) 
		{
			// Local variable to work on (this does not look very efficient)
			var current = currentDateTime;

			// Do slightly different things depending on what the type of roll point we want.
			switch(rollPoint) 
			{
				case RollPoint.TopOfMinute:
					current = current.AddMilliseconds(-current.Millisecond);
					current = current.AddSeconds(-current.Second);
					current = current.AddMinutes(1);
					break;

				case RollPoint.TopOfHour:
					current = current.AddMilliseconds(-current.Millisecond);
					current = current.AddSeconds(-current.Second);
					current = current.AddMinutes(-current.Minute);
					current = current.AddHours(1);
					break;

				case RollPoint.HalfDay:
					current = current.AddMilliseconds(-current.Millisecond);
					current = current.AddSeconds(-current.Second);
					current = current.AddMinutes(-current.Minute);

					if (current.Hour < 12) 
					{
						current = current.AddHours(12 - current.Hour);
					} 
					else 
					{
						current = current.AddHours(-current.Hour);
						current = current.AddDays(1);
					}
					break;

				case RollPoint.TopOfDay:
					current = current.AddMilliseconds(-current.Millisecond);
					current = current.AddSeconds(-current.Second);
					current = current.AddMinutes(-current.Minute);
					current = current.AddHours(-current.Hour);
					current = current.AddDays(1);
					break;

				case RollPoint.TopOfWeek:
					current = current.AddMilliseconds(-current.Millisecond);
					current = current.AddSeconds(-current.Second);
					current = current.AddMinutes(-current.Minute);
					current = current.AddHours(-current.Hour);
					current = current.AddDays(7 - (int)current.DayOfWeek);
					break;

				case RollPoint.TopOfMonth:
					current = current.AddMilliseconds(-current.Millisecond);
					current = current.AddSeconds(-current.Second);
					current = current.AddMinutes(-current.Minute);
					current = current.AddHours(-current.Hour);
					current = current.AddDays(1 - current.Day); /* first day of month is 1 not 0 */
					current = current.AddMonths(1);
					break;
			}	  
			return current;
		}