using System;
public class MainClass{
        /// <summary>
        /// Gets the end of year.
        /// </summary>
        /// <param name="date">The date.</param>
        /// <returns></returns>
        public static DateTime GetEndOfYear(DateTime date)
        {
            return new DateTime(new DateTime(date.Year + 1, 1, 1).Ticks - 1);
        }
}

   
     

using System;
public class MainClass{
///

/// The date. ///
public static int GetDaysInYear(DateTime date)
{
if (date.Equals(DateTime.MinValue))
{
return -1;
}

DateTime thisYear = new DateTime(date.Year, 1, 1);
DateTime nextYear = new DateTime(date.Year + 1, 1, 1);

return (nextYear – thisYear).Days;
}
///

/// The date. ///
public static DateTime GetEndOfQuarter(DateTime date)
{
int daysInYear = GetDaysInYear(date);
double quarter = ((double)date.DayOfYear) / ((double)daysInYear);

if (quarter < 0.25) { return new DateTime(new DateTime(date.Year, 4, 1).Ticks - 1); } else if (quarter < 0.5) { return new DateTime(new DateTime(date.Year, 7, 1).Ticks - 1); } else if (quarter < 0.75) { return new DateTime(new DateTime(date.Year, 10, 1).Ticks - 1); } else { return new DateTime(new DateTime(date.Year + 1, 1, 1).Ticks - 1); } } } [/csharp]

   
 
using System;
public class MainClass{
        /// <summary>
        /// Gets the end of month.
        /// </summary>
        /// <param name="date">The date.</param>
        /// <returns></returns>
        public static DateTime GetEndOfMonth(DateTime date)
        {
            return new DateTime(new DateTime(date.Year, date.Month + 1, 1).Ticks - 1);
        }
}

   
     

   
 
using System;
public class MainClass{
        /// <summary>
        /// Gets the start of month.
        /// </summary>
        /// <param name="date">The date.</param>
        /// <returns></returns>
        public static DateTime GetStartOfMonth(DateTime date)
        {
            return new DateTime(new DateTime(date.Year, date.Month, 1).Ticks);
        }
}

   
     

   
 
using System;
public class MainClass{
        /// <summary>
        /// Gets the end of day.
        /// </summary>
        /// <param name="date">The date.</param>
        /// <returns></returns>
        public static DateTime GetEndOfDay(DateTime date)
        {
            return new DateTime(date.Ticks - 1);
        }
}

   
     

   
 
using System;
public class MainClass{
        /// <summary>
        /// Gets the days in year.
        /// </summary>
        /// <param name="date">The date.</param>
        /// <returns></returns>
        public static int GetDaysInYear(DateTime date)
        {
            if (date.Equals(DateTime.MinValue))
            {
                return -1;
            }

            DateTime thisYear = new DateTime(date.Year, 1, 1);
            DateTime nextYear = new DateTime(date.Year + 1, 1, 1);

            return (nextYear - thisYear).Days;
        }
}

   
     

   
 
using System;
public class MainClass{
        /// <summary>
        /// Gets the days in month.
        /// </summary>
        /// <param name="date">The date.</param>
        /// <returns></returns>
        public static int GetDaysInMonth(DateTime date)
        {
            return DateTime.DaysInMonth(date.Year, date.Month);
        }
}